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Testing Time: Fixing the Seachem Tidals Bypass


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Hey everyone,

Well, it's finally here. Construction day.  I have a few hypotheses that'd I'd like to test out, but obviously I'm a sample of one.  I do have a bit of experience battling these stinkin' things and I feel like it's the right time to dive in and figure out the best way to solve these issues.

The goal being, after these tests are completed I can provide a guide for others with a tier of mods to make on their HoBs and to resolve the issues they have as best as possible.  Tier 1 being the least effort and subsequent tiers requiring a bit more effort. 

One thing I am specifically not going to do is to jam a bunch of sponge in the pump area as a method to try to stop mulm from going into the pump area through the swiss cheese that is the skimmer and the pump housing cover.

Let's get started with Tier 1 (sponges) and I will sketch out the concept for next steps.



I want to reference this video as a premise, but obviously the goal being we want to make this visually look good.

Problem Statements:
1. There is an excess of openings on the intake and this forces most of the intake of the filter to be provided via the skimmer, pump housing cover, and minimally from the inlet pipe itself. The reduces the viability of something like an intake sponge and causes many issues for nano fish, flat bodied fish, or plants being sucked into the intake.

2. The flow path of the water itself in the pump is not well defined and the water constantly avoids filter media and filtration. 

3. The pump is incredibly strong and might be too strong in some instances. the flow into the HoB filter basket can cause bypass simply due to the flow strength.  (more on this later)

4.  The filter basket design is very restrictive and tolerance on sponges is often undersized, which caused bypass when you do manage to get the water into the filter media basket.

5. Because of flow strength, media order, and bottom to top flow design, it's difficult to use something like purigen because of the high flow / bypass that forces lighter media off the top of the media basket and into the tank itself fairly easily.

I want to attack these 1 by 1 and demonstrate each of these, but I will do this in a follow up post.

First up we have the easiest thing we can do. Simply cutting new sponges that allow water into the basket itself. For the Tidal 35, this alone has resolved most of the bypass issues and has given me a few notes.

Let's take a look at why this helps and what is really going on.  If we look at the filter box itself and the basket, this is what we see.



There is a bit of space below the basket itself.  If Seachem feels like it, they can resolve issue #3 by adding some baffles in this space.  This also means we might be able to use something like eheim mech (thanks pondguru for the idea) to diffuse the flow itself. The basket does have "baffles" or sort to hold up the sponge and this is partly just due to manufacturing and wanting to have a clean edge and encourage flow internally.  It also gives the sponge itself a flat surface to rest on, somewhat.

What I have realized is that by adding more media or adding crushed coral in the basket, this compresses the sponge into these grates and emphasizes the bypass even further.  From the typical "pond foams" that you can purchase for filter mods with the bumps you'll end up with something that is slightly thinner in profile and this might also be easier to compress when loaded with heavy media.


So, if we take a look at what is really going on internally we see the standard foam (right side above) which sits flush against the openings.


If we swap this foam out with "bumpy foam" you see a bit of room for the water to flow into the filter basket.


Realistically this does not fix anything, but it really does give you a bit more time for the basket to do it's job. Right now, after a deep clean I can see bypass almost immediately with a stock sponge.  Normally I prefer to run 2 sponges, but there is often an issue with the seachem products. As mentioned above there is often some gaps out of the box. (Issue #4).

Second to this issue, as you add more layers of sponge, each layer needs to have a slightly larger dimension outward. the media box itself opens up as it increases in height. This means that cutting sponge can be tricky, but it's very easy to achieve this.  Once you get the hang of it, there isn't much difficulty and it can easily be done with a pair of scissors in between a water change.


Here's the setup.

I am setting up a NEW 29G aquarium in the living room, and I have the video above as a template. I also have my own experiences and testing, mods, and attempts to fix this issue previously on 5-6 versions of this product. I've used everything from the 35 to the 75 for a few years on each model in a variety of tank setups.  Right now I have a newly purchase Tidal 55 for the new tank.  I am going to be modding the filter and adding those parts into the existing setup one by one.  I will have 1 stock filter, 1 modded filter, and be able to adjust things to test what really works well and what fixes issues (or adds more).

I also want to reference this post as a deep dive into a lot of my struggles for those who want to see other photos and read a bit more about my past testing / current setup

I will go ahead and record a video of the pump now, then add in the sponges and show the difference in flow.  If there is an improvement, I'll continue to monitor things as the week progresses.

One thing I will note as a final thought, is when I pull apart the filter, I try to pay attention to how clogged the sponge is and where is the much appearing at. Last time I cleaned it, there was a very defined grate/input pattern on the sponge and it was limited to the input side of the basket. The sponge itself was not clogged and it was only in the basket for a few days.  all of the water was bypassing over the back of the basket and pretty much stopped going through the sponge/media.

Let's get to it!


FAQ Post here.


Edited by nabokovfan87
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Phase 1: Replacing the foams only with results.  I apologize for the poor filming attempt, it happens.  You can see those compression marks on the bottom side of the filter sponge, which does show the basket itself is pretty loaded up and the media is crushing the sponge.  This may lead to an alternate use case where you remove the majority of any other media and run only sponges. You'd have to cut them yourself, but there is definitely potential for this setup.

Phase 1a: Showing the foams being replaced "fixed" the bypass once I adjusted how much stuff is jammed into the media basket. (It's full because I'm having to run crushed coral).  Bypass is no longer from the rear of the HoB container, but the lower front window.

Phase 1b: Showing a potential fix that is very common to anyone who doesn't want to fill holes in the media basket or cut out the bottom section of the basket to improve flow. This is the "window" cutout that I will highlight when I show basket mods.  As you can hopefully see, there is still bypass on the left side of the sponge. It's mostly removed the bypass issue and there is water flowing through 3 sponges at this point.  For most users this is going to be the setup for your filter.


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Next up, let's cut out this basket and "attempt" to do it without power tools, without making it look like someone took a chainsaw to the plastic, and without completely destroying the plastic.

My idea was to use pliers.  These, specifically will probably be the best tool for the job.


Here is my plan:


Using the pliers, I'd like to cut out these section. Leaving a part of the bottom grid intact but opening the bottom of the container in such a way that we aren't using a drill or relying on small holes (these did not work for me previously, so if you go the drill route, you need at least 1/4" dia holes.

I have the clogged sponges, I have the filter running, and I will show the before and after.  I am not going to clean any sponge, I will simply move the dirty media to the new basket and let it run with the cutouts.

Here is what it ended up looking like:

I may end up taking a file or some sandpaper and cleaning this up a bit, but for now this will "work" for our testing purposes.

Here is the before photo, sponges as they are right now in the filter, and the before video.


The key note here being that the coarse sponge isn't doing much cleaning right now because it's not getting very much flow through the sponge itself. This is very evident when looking at the sponge because while there is "some much" on the surface, it's very light and not something I would expect to be "clogged".  The second foam in the pile, the black one is slightly more fine, and it's pretty much clean without any gunk on it whatsoever.  This is pretty typical.

I also included a photo of the basket.  We see that the filter itself is bypassing very badly before any modification. The input of the pump was actually filling the little black shelf with much as you can see in the video.  This often happens when there is high levels of bypass.

Here is the after:



You can see that this is a VAST improvement compared to where we started, but there is clearly some severe bypass still happening in the window cutout on the front of the basket. Overall I would call this a "minimal effort" fix for the bypass but I do believe this is not solved by any means. I will be very interested to see how this is running in 36-48 hours and how things change with the next big change.


Edited by nabokovfan87
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Looks like after the 48 hours, no change.  So this worked pretty well so far without too much hassle or effort.

EDIT: It looks like *now* we have the standard rear of the basket bypass today.  I'll clean it out tomorrow and take pictures and proceed with the next step!  (Lasted overall about.... 80-96 hours before it started to bypass the media)

Edited by nabokovfan87
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Minor update, I don't have a new "fix yet" for the specific issues, but I did clean the filter and optimize the basked slightly further.  I also prepped some of the parts for when I do use the black silicone on the few parts I need to.  I also need to verify this, but I think seachem added an in-line change as a product improvement to help reduce vibration noise and improve fit on the pump slightly.  It also might be flow related, but I don't have any real way to review that.  More details below.

Here is the details on the cleanout and the potential improvement someone can see with the upgrades so far on their filter.

This is the "window cutout" sponge that I use to protect the media from much.  This shows you how bad it is to have this cutout in the basket itself.


I wanted to record this for posterity.  Essentially, this is just to show the fitment on the sponge being slightly loose and the water was able to push it upward and expose some bypass avenues.  This could simply be movement when I removed the basket itself, but it's worth noting.  I did re-cut sponge to fit a lot more snugly into the basket.  Those are in there now and I have them for future use.

This is the underside of the basket, showing the amount of muck trapped in the sponge before it was moved.  Improving the flow into the basket itself shows how the restriction is impacting overall performance.

This is the top of the sponges after removing the media itself. I was hopeful at this point that I would see a lot of muck on the underside of the black/fine sponge.

There was some, but not much.  This leads me to believe it's just remnants from the window cutout.

Here is the medium density foam. I am showing this to highlight the slight improvement of switching out from the flat style sponge to the bumpy sponge.  I will run a test with the original sponge compared to my custom fit sponge after all the improvements have been made.

Secondly, here is the cutout details I did to clean up the basket itself and the intake tube blockage.

I used the sanding disk to remove any burrs or sharp edges. I recommend going slow and taking your time, let the wheel do the work. 

The "cleaned out" window is the one on the right side of the basket with the pliers only cut on the left/center side of the basket.  You can do this by hand with a file or a sharp blade and sandpaper.  If you use something like that, be sure to be careful and protect yourself from any nicks if the blade jumps on you. 

I would try to leave the "tall posts" intact on the right and leftmost edges of the cutouts.  These give the sponge a flat surface to rest against when installed and filled with media.


Secondly I want to note that the basket itself is a pretty soft material.  In terms of filter boxes it fits exactly what you need it to do and the engineering choice for this material was a very good one. It's pliable and handles movement well but definitely strong enough in terms of it's rigidity as well as taking some abuse day to day.  The black plastic is a lot stiffer and reminds me a lot of other plastics I've worked with.  It's very hard, not very pliable and the dimensions themselves are pretty thick in some areas.  This does mean that some tasks like removing the pump cover can be difficult, but it also should mean that overall the tolerances on the black pieces of the filter are pretty good. This also means that the tolerances on the white plastics might not be as tight as they could be when you need them to be.



Finally, of note....

There are these pads added to filter cover itself.  It may be there to help "seal off" part of the flow from the grate on the right to the intake tube.  Because the pads themselves are very soft, I think their only use is to reduce vibration noise of the pump itself.


Edited by nabokovfan87
Fix Autocorrect Issue.
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Update #2 for the week. 

This is going to be, by far the MOST COST EFFECTIVE way for seachem to fix this product in-line.  In terms of the production cost, you remove a cutout, which saves manufacturing time and money.  Second, this is the easiest thing to mail to customers without costing the company itself an arm and a leg to fix.  You would mail out a small envelope of sealant, a small piece of plastic, and directions.  In terms of engineering time, you're talking 3-5 days of testing (if that) and then you're talking about what amounts to 1 day of paperwork and a few months of planning/production cost.  If they modify the hard tool and incorporate this into the design itself, you coordinate with the tooling manufacturer and they rework the tool (if this isn't done on the manufacturing floor).  You then are improving the strength of the part, improving tolerances, improving flow of the part in that area of the tool.  It's a very minor improvement, but the point to drive home here is how minimal effort this actually takes. Anyone who knows how to use the program could get the paperwork done in 2-4 hours and have it released by the end of the day.  This all assumes they verified the testing results and accepted them as an improvement in the design.  This gives you downtime of about, 4-8 weeks and samples are sent for approval.  In total, you're talking about VASTLY changing the flow of the basket, easily modifying something, cheaply fixing it in the field, and reducing cost to make up for the change as a result.

Tier 3a (prep): I couldn't find my sheet of scrap lexan anywhere so I opted to use a piece of scrap trim from an aquarium lid.  We all should have some of these sitting around, and so it's an easy way to patch this hole.  I did use the black silicone here, I do not know if this will hold long term.  Worst case, I can remove it and then use superglue that is fish safe.

I just used a piece of scissors, cut it to size with overlap around the edge and glued it internally as to not disturb fit when loading the basket inside the HoB.


It doesn't look great, I would prefer clear, but for the sake of not making a trip to the store for something I won't see, I'll allow it.



For now, I did opt to leave those other slots open to allow bypass through them.  If they are an issue long term, it won't be difficult to patch them.  I'd like to run some tests at this point after it cures before progressing to fill anything further. 

Edit:  I forgot to mention, if someone has one of these and a 3d printer, might be a nice little side project and take about 10 minutes to measure it.  The "drawing" won't take too much effort in the CAD software and you could easily print these and mail them out if you feel so inclined.  3d printing them gives you the nice added bonus of being able to fill the thickness needed with some precision compared to what is lying around.  I'd probably shoot for .063 thick material if I had to guess.

Update for the sake of the curious: I was checking on the filter flow, bypass, etc. and I noticed the "often rare" bypass by the input chute of the filter.  Here is the video showing off the bypass, demonstrating the cause of the bypass by removing it, and then restarting the bypass to verify that this is the cause.  I'm thankful that I was able to capture this because it shows how detrimental some of these design choices have been for the filter basket and how much it would benefit the design to fix some of these issues.



Edited by nabokovfan87
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Minor Update.  Everything is prepped for testing and currently going to let the silicone cure.  I was trying to fix the adhesion on the basket and ended up pushing slightly too hard to try to get the nossle underneath the piece of plastic and pulled off the bottom edge.  I cleaned it off, did a much better job getting everything done.  As for the rest of it. EVERYTHING is very easy to fill with the silicone and do so neatly apart from the skimmer. It's just slightly too large of a cut for the bead to sit cleanly, but I tried my best to give it a clean edge on the exterior. I'll probably end up using a long blade and try to clean up the inside once it cures entirely.

Here's the photos for reference.




Because I have spare parts to do so at this time, I can basically test these in whatever method I need to. I can patch only the skimmer, I can patch only the intake.  I can patch only the basket and sub in whatever need be as the results dictate.

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I went ahead and installed the basket today. I have ~2 days to run it before I am going to be running meds for a little bit.  I don't want to run Ich-X and discolor this new basket so I will check in on things after it's had time to gunk up.

When cleaning the old basket (no mods at all) I did notice the sponge did absorb a bit of mulm and while there was bypass issues, it was "working" so to speak to an extent. It may have just been a time thing and I don't want to say anything definitive here, but it is good to see improvement with only the sponges in place that has some meaningful results.

I cleaned the sponges, placed them in the modded basket.  I took a deep breath and felt a little bit of impact from the gravity of the moment.  Honestly, this has been something weighing on my mind for a long time and it's so nice to be able to see what on earth this actually does. Engineering an issue aside, It was nice to be there.

The flow in the basket was dramatically improved. Initially, that's all I can really say at this point. Instead of the flow going through the window, it was going through the sponge and through the bottom of the basket itself.

EDIT:  I added meds today (7th) so I'll let the basket run until the first WC and then I'll go ahead and swap it over to the new one. This should give it about a week and I will check on the bypass issue after that time.  I am going to run Ich-X and such after I run the paracleanse, so I didn't need to worry about discoloration yet.

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Because I am essentially on hold for a few days with the project I wanted to take a moment and specifically discuss one of the reasons why I have ended up going through this exercise.  Pondguru.  Needless to say I really enjoy his content and I look at his methodology and advice for filtration.  I might not have the filter, but I do enjoy watching him talk through them.  I highly recommend learning about filtration from him and specifically his videos on building his massive pond filters (and updates).

Years ago, he worked on the Tidal 110 and later on he came back and did a newer update with the Tidal 55/75.


I tried this in my 35, 55, and 75 and I had a few issues. 

The first issue is just the bypass in general and how much it ensures the water doesn't interact with the media. He does explain that it's a pretty strong pump.  In terms of his intake path he missed the middle intake that is around the pump housing. It's not really a big issue, but it's just something to keep in mind when we discuss the flow path.  The other disclaimer here is that he typically doesn't run the filters. He doesn't want to ship them back slightly wet.

The second major issue is something we've been discussing above, the weight of the media and crushing the sponge.  Once all of these changes are done, it might not be an issue, but that is something to keep in mind.

My experiences with his method:
I really liked the idea of adding sponge into the chute before the water hits the rest of the sponge. I tried bumpy foam as well as the seachem foam in mine. In one of the filters it worked for approximately 12-24 hours before the pump simply rejected having the foam in that position.  This forced water to shoot at the lid.  The other attempt I had with this foam in the chute cavity, it rejected the foam immediately and just started splashing water all over.

I did later find out you can remove the cover above the chute.  I ensure the plastic cover was fully installed, the basket was installed again, I tried drilling holes and I tried giving the chute some "room" by cutting the foam in half.  Meaning, I tried to fill the chute partially with foam to catch some muck, but allow the water to pass without restriction if it wanted to.  This helped, but again after a 24 hour period I had to remove the foam to stop splashing.

The fact that he cut his own sponges, they actually fit well, and they have the dimples, solves a lot of issues for a lot of people. I highly recommend that at the very least and his use of these foams has been the single best successful mod for these HoBs. Water height issues I'm showing off, it's something that he obviously can't see because it's not running.  Especially the issues with the window cutouts.  The media he uses is very compact and does cover the "window cutout" but I can guarantee you that the water is going directly through that are without really going through the sponges.  Same thing with the intake filter. In my estimation, at best you're getting 10-15% of your input from the bottom of the intake pipe itself. The majority of the flow comes from the middle section (pump cover) and the skimmer openings.  Because of this, having the intake there is nice, but it really doesn't do much in terms of the mechanical filtration benefits.

In fairness, he setup this filter with the assumption that it works as designed. So I can't fault him too much for not cutting out holes in the basket or anything like that.  I bring him up because he has specifically stated a few times in his videos that what he tries to do is provide a setup to start the conversation on how to setup the filters. It's a good way to view it. He points people to the comments where someone else can post an experience or provide feedback.  He also has said many times that if there's "something better" he's all ears.  One day maybe he'll see this, but the fact that he is encouraging to have a conversation and to discuss the setup of the filter has been a huge motivation for me to take the time to do something like this. If it ever makes it way to him, awesome, but I can guarantee you that no one should buy a product and "have to" modify it to such a degree to get it to function as designed.

I'll toss a few photos below to show what's going on with the filter currently.  Something I wanted to highlight for the tank itself right now is just showing where things tend to get stuck on the intakes, telling me where the flow mostly comes from.

Usually there is a little piece of Anubias nana petite floating around the tank and it's either caught in the skimmer or in the pump housing grates.  I couldn't even find it tonight.  The poor little thing must've gotten sucked into the skimmer or something.

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Results of the first run.  I did run it a bit "longer" than I'd like to, but so goes it.  I am running crushed coral beyond the normal items in the basket. That being said, with the crushed coral there is always going to be "bypass" so to speak.  The height of the water is just naturally above the basket itself.  Given the hight of the handles (and I have broken one before trying to pull the basket out) that is a good potential point to have a safe tool change where you can add some use to the product.  Something to consider if they do ever add a new one.

A few other notes, I did verify two things I had tagged earlier as "design improvements" and they are both on the older version I do use.  So I am going to edit the above to remove that information.  (the hooks you'll see below was one of them, the other was the foam pieces inside the pump cavity)

Here's what I saw pulling the foams.  I did set them up for a 2nd run, and I did slightly lower the flow so that there is a longer period without bypass appearing.  I am very encouraged seeing the flow on the sponge and on the media itself.  This isn't the norm, which means some of these improvements are resulting in a positive change.  It's definitely not perfect yet!

You can see some "clean" blue sections.  I would argue these are due to the high flow pushing the gunk internally through the sponge in those two regions.

Top of the medium density sponge, some gunk seems to be here, but not more than normal.  I was expecting more.

We do see some muck a bit better here. There is a path we can see that shows the muck going vertically upward when installed into the filter. (Apologies if this doesn't make sense)

The silicone seems to be holding on fine, again, very early results.

This is where I am seeing bypass still.  I don't know if this is "acceptable" or not, but it's something to keep an eye on.  If the intake is resolved, it might not happen because there would be a prefilter sponge and some of the larger much would get caught before it gets to the basket.  I may run a test with the modified intake, but I saw this and thought it would likely result in needing to seal the basket in those small cutouts.  Again, the "majority" of the bypass is pretty easily seen at the top of the basket. We will see how things develop as more tests are performed.

A good amount of muck on the first sponge

We do see some muck on the 2nd sponge.  Much more than before and the good news here is that you see it internally on the sponge pores, meaning that it's being pushed into the material and no longer just getting to this sponge and then bypassing elsewhere.

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Phase 3: Modified intake (No skimmer, intake tube only)

It's been a long time coming, but I finally put in the parts to run some tests with the modified intake.  I will need to see how much this changes the flow in the tank and how much input pressure this puts on the intake itself. My hope is that there isn't any issues with the modifications with regards to the pump functioning, and this simply means what we have is an "improved" design.  What I will say is that from my initial thoughts, the mods are extremely subtle and you won't really see them if you don't know what you're looking for.  You won't see the blue dial in the water, you won't see plants and other things stuck on the mid-level and skimmer intake anymore.  It should be a much more sleek installation all things considered.

I briefly recorded a video, but this was after a water change and the tank was pretty full of bubbles. I wanted to show the filter working directly following it's first power on.  Over the next few days I will keep an eye out for noise, and I will go ahead and see how things change with regards to the flow in the basket itself. I am currently running the old basket so I can modify the improved design by sealing those final slots.

A final note on the modified basket run.  there was a lot of bypass, again, due to the crushed coral.  I did see a little bit more muck in the coarse pad and I was pretty surprised how much it had removed from the water in such little time.  I didn't take any photos or record anything because it wasn't too spectacularly different than the expected results shown before.  I saw a lot of muck in the slots, on the areas where there was bypass, and in the bottom section of the basket.

I will seal up the basket tomorrow, then go ahead and let it cure and replace the original basket running now with the fully modified design.

Edit: Here's some night shots, sound test, and views of the filter installed.




Edited by nabokovfan87
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This is amazing!!!! I run these filters on 3 of my tanks and I’m definitely going to be making some adjustments. Not only is this helpful but it has made for very good content as well in my opinion. Many thanks, I’ll be watching for any future projects and updates as well…

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On 6/19/2022 at 12:48 AM, CJs Aquatics said:

This is amazing!!!! I run these filters on 3 of my tanks and I’m definitely going to be making some adjustments. Not only is this helpful but it has made for very good content as well in my opinion. Many thanks, I’ll be watching for any future projects and updates as well…

Thanks! I really appreciate it.

So far everything is doing ok as far as performance with the modified intake. It's going to take me a little bit of time gives some issues with the tank (treating for worms), but it's amazing how quiet and sleek everything looks.

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Minor update and this is more about the state of my tank than anything new on the filter.

*A tale of warning*

So I have been treating with meds which means my general hands on with the tank isn't as much. I want to let things "settle" to give the fish a stable environment. Because of that, I had the old basket in the filter, modified intake, should've been a good long test. Then I got sick, haven't been upright for an additional length of time. After the first week of meds I noticed worms swimming in the water column. I was treating for internal parasites, so this was a concern.  I had finished the first course of treatment and returned the tank back to running on only the HoB after a second water change.  Over the next week, two weeks, I noticed flow seemed very poor. I left it and kept an eye on everything and just assumed it was my own perception.  I lowered the water level so there was more of a waterfall but things seemed to still be too slow.

This morning I cleaned out the filter. This is the filter AFTER I cleaned the basket, but BEFORE I cleaned the pump. This is to give you an idea of the flow issue I was experiencing under "normal" maintenance. Be it, at an extended duration.

Second, here is the video AFTER cleaning the pump.

There is a clear issue with the pump being clogged and it's lead me towards another question. Does it matter what side of the pump the intake is on. For this run I have the same setup, and the intake tube is on the pump intake sside I may have to see if it will fit in the opposite position and if this does anything to help keep the pump from clogging. The easiest thing to do is to run an intake filter.

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  • 2 weeks later...

I use my Tidals as bio only with a coarse intake sponge. The bypass is not an issue for me.   My only issue with them is the skimmer.  I don't need it nor do I want to listen to it slurping if the water level drops a bit.  I have considered sealing it but didn't want to ruin the filter altogether.  Do the filters run OK with the skimmer section sealed?  Nice series BTW.

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On 7/3/2022 at 9:37 AM, Gwallace said:

Do the filters run OK with the skimmer section sealed?

I have ran three or four tests so far. I just setup the fully modded basket last night with the modified intake. I'll let you know here shortly. I have everything in the basket sealed now and this is the first test with those little slits sealed up as well as the window cutout.

On previous texts, I do notice some issues. so it isn't perfect but I think there is a happy medium that will work well and remove the skimmer.

On 7/3/2022 at 9:37 AM, Gwallace said:

Nice series BTW.

Thank you!

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This is great stuff! Well done!

This has given me some direction to improve my Tidal 35 outside of throwing it into a cabinet as an "emergency only" filter. Of every filter I've used, this has been my least favorite. Which has been frustrating since the build quality is quite nice. 

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On 7/6/2022 at 9:03 AM, Minanora said:

Tidal 35 outside of throwing it into a cabinet as an "emergency only" filter.

Definitely a good nano filter for me, especially if I can make some sort of a pre-filter.  Why they didn't bother designing an actual intake is hillariously bad to me.

I saw a video of someone who had moved recently and they thought they "lost the intake" and didn't set it up.  I had a little giggle on that one.

I do have an idea / recommendation for final mods, but I want to run some more tests.  Given the issue on my tank (diseases section) right now with the parasites and how heavily it's impacting the filtration I don't want to pass information without running more tests. I appreciate all the feedback.  More coming, soonish when I can run 3-4 more tests!

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On 7/6/2022 at 10:38 AM, AquaHobbyist123 said:

Lemme know how that goes.

Minor update, and the progress seemed to be better than I was expecting, which is good to see.



On 7/3/2022 at 11:02 AM, nabokovfan87 said:

I have ran three or four tests so far. I just setup the fully modded basket last night with the modified intake. I'll let you know here shortly. I have everything in the basket sealed now and this is the first test with those little slits sealed up as well as the window cutout.

This was the last setup, i.e. "fully modded" setup.  I won't reveal too much, but I do want to reveal some thoughts and the logic going into these final few tests.

I do have a worm, gunk issue in the tank, which means the HoB was pretty clogged and some tests needed to be repeated.  After repeating the test above, instead of the filter lasting ~2.5 days before showing bypass, I checked the filter today (Sunday-Friday, approx. 5 days) and things were not bypassing.  I did notice some moss in the pump region, some gunk in the bottom of the HoB box, but nothing as bad as I was expecting.  I would consider all of this as a normal behavior and the pump was not restricted in any way.

The tank is currently setup with:
1. Fully modified basket.
2. Skimmer is closed off
3. Standard intake (mid and bottom intake with the blue dial still on the intake)

The logic here being that this provides a slightly easier time for the gunk to go into the pump cavity.  If the pump housing itself is slightly too narrow, not enough capacity, and the impeller is slightly slower than it need be, the pump can slow down pretty heavily.  My hope is that this test shows me that from day 1 through to day 7-14, that the pump itself is not being stressed in any way.  This is what I would call the "middle ground" solution. 

My main observations here are going to be to determine if there is any restriction on the pump, what is the flow itself on the output of the HoB compared to the fully modified setup and how does this setup work to keep fish out of the intake itself.

Here is what the filter looked like during the clean out as well as the foams.


These are the foams. Not a lot of muck on the fine foam (black) but the first photo is of the blue foam (medium pp1).  I apologize for the blurriness on the photo.  I looked at the foam after taking the photos and I didn't see many or a ton of worms, I do see a few bits of moss, entirely normal as mentioned.20220708_202450.JPG.6391eb18ecd9d5be0e0b32f194fa1c5b.JPG20220708_202501.JPG.f6a32053385c97713a185fcec1f8614f.JPG

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Adding this here for later use.  IF you have one of these things, I highly recommend this method for cleaning.  Again, I don't use foams for biological filtration, only mechanical.  You'd want to preserve the bacteria in tank water and clean the filter (especially the pump, skimmer, and intake) in this way to ensure it's functioning properly.  I post this partially because it's an amazing tank to me!!! But, I also really appreciate the mythodical nature of this cleaning for this filter in particular.  Enjoy 🙂

A note regarding the impeller, there is a cover, you take that off, it's difficult to do by hand on the 75/110, much easier on the "cheaper" versions of the pump on the 35/55 and can be done with your hand.  You take off the cover, please do this!, and then you remove the impeller, clean it with the brush as shown, clean the shaft cavity as well, then add silicone grease (scuba shop has this or amazon), and then reinstall everything onto the pump and re-assemble the HoB.

This is what I would consider as a "deep clean" and this should be done at minimum every 1-3 months.

Alright, I'm amazed.

I JUST found this and had to post it.  What a great video about mods and trying to fix this filter with "tier 1" fixes.  If anyone has some gutter guard they want to send me..... I'm down to try that out as well, seems like a brilliant idea to fix the foam being crushed and give the filterbox a chance to work.


Edited by nabokovfan87
added impeller instructions
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I did a big gravel vac on the tank during my worm hunting and general maintenance day.  I did not check the pump cavity for worms, but I did see bypass immediately after cleaning.  This might've just been as simple as the level on the HoB being slightly too steep, but I did record it for the sake of sharing. (there's some tips/tricks I'll get into one day regarding how to mess with the angle to reduce bypass)

The flashlight has new batteries, so I apologize for the harsh brightness.

The bypass seemed to be focused on the right side, flow going from left to right (and top to bottom, then bottom to top).  The mass of the water hits the right side of the HoB and it looks like it's filling the chamber where the blue indicator sits.  This was overflowing into the basket.  What I noticed after cleaning the basket and foams was that the water level was pretty high and in order to reduce that height the flow itself had to be turned all the way down.  Secondly, the meniscus of the water was essentially "leaning" into the basket in the rear region of the HoB where we typically see bypass.  In the video you can see this leaning on the handle area as well.


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48 hours later and the bypass is pretty bad. My next test I am going to run I will run with the original sponge and the standard media bag nothing different in terms of media. I'll break down the details when the time is pertinent, but I wanted to record this for posterity. And let's be clear.... A filter telling me to "maintain your filter" right after cleaning and best case 36-48 hours after cleaning isn't acceptable.


Filter bypass as setup, before adjusting angle.


Filter bypass after adjustment of angle, maximum angle of deflection leaning downward back to front (into the tank, rear of filter is the highest point):

You can see the 5 points of bypass evenly distributed on the back of the basket. This correlates to ribs on the basket itself that can be seen through the plastic.


Bypass on the handle as shown in the video, now it's free flowing.


Bypass on the input side as well, there is also a pool of water on the chute region where the water inputs the media chamber. This is typically a sign of extremely bad bypass. (Black section shown below should be dry, especially no water movement)


I will end up removing the chute piece and verifying that the internal cavity of the chute is clear of obstructions. To do this, you remove the blue clip that locks the basket into place and then you lift upwards on the black plastic piece. There is a small shaft that leads from the adjustment knob down to the input chute opening.

My hypothesis here is that by adding the unmodified pump cover, this caused an easier time for the water to enter the pump chamber. This also means that the flow may have been increased just enough to cause too strong of flow into the basket itself. The resistance of the foam, porosity itself is causing the water to flow elsewhere. Either modifying the sponge porosity itself to reduce resistance or diffusing the flow in the chamber of the HoB might be the method to diffuse the flow just enough to keep the water level low enough.

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I swapped the sponge out with the standard, original seachem sponge.  Currently we have the modified skimmer, modified basket, original sponge, original intake, original pump cover.

I will run this test, potentially two or three versions, and then report back with some final thoughts.

Here is the bottom of the basket when cleaning, bypass demonstrated in the post above, you can see this is not very clogged with muck.  Again, this bypass issue is pretty fickle and difficult to resolve easily. 

For the sake of clarity, here is the other pertinent views of the filter box.  There is some moss in the bottom of the HoB cavity, which isn't anything out of the ordinary.  The pump was clean of any worms and looked like it had just been cleaned.  Clearly it is working well, so I didn't worry about cleaning the impeller shaft itself.  The second photo below is of the chute cover and the chute cavity.  There isn't any blockages, the adjustment dial was reinstalled and cleaned just for the sake of doing so.

One way to "fix flow" might literally be to stuff that cavity with sponge, but I have a few other ideas to try first.



For the sake of demonstration only, this is the intake sponge I have for testing. I'll end up ordering a smaller one or looking for one.  This is designed to fit well on the Tidal 75, but does not really work on the tidal 55. This should be the ACO "large" sponge filter based on dimensions.

You can see it pushing pretty hard against the glass and rim of the tank, forcing the HoB at an awkward angle.  It's easy to tell if you look at where the rim of the tank is and where the HoB is designed to rest.



I removed the intake sponge, set everything up and verified the level of the HoB itself.  I then reviewed and measured the bypass on the filter.  There was some pooling on the chute itself, but not anywhere else.  This is acceptable.  The water level was about 1/8" below the rim of the basket.  That isn't great. Especially considering we removed a layer of foam from the basket itself and the water level should be lower.  There's nothing in the chamber to restrict water right now, so the full force of the pump is going into the foams. I fully expect this to clog pretty quickly, but we'll see how many days until the basket starts to bypass on me.

As an example, this is a photo from earlier in testing of a sponge on the "window cutout" of the basket.  When we compare this to the sponge above in this post you can see how much capacity there is for this sponge to clog a bit more with detritus.  I would fully expect a filter to last and operate a bit longer than indicating maintenance is required.


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