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Testing Time: Fixing the Seachem Tidals Bypass


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On 1/15/2023 at 11:39 PM, nabokovfan87 said:

@TeeJay After the mod to the mod to the mod.... It's back again for a second time.


If you look at the left where the skimmer usually is, you can actually see bubbles rise up to the surface as the noise pops.  Very weird.

I know that huff of frustration at the end ..I know that all to well

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  • 2 weeks later...

A little bit of a follow up on things.


I have been running this filter without the fine foam in for a little while now, I can verify above, but let's just call it close to a month at this point.  I did have to remove one of the sponges, but this is simply put not due to the amount of sponges, but just a demonstration of why fine foam does matter.   On the course sponge I did see improved circulation, but not enough to justify that it's "fixed the bypass" at all.  Ultimately it gave me slightly longer until the bypass happened, but it did still happen and did so a lot quicker than I view as acceptable.  I will have to raise the height on the basket, remove media, or something to lower the water level.  Overall this should be 90-95% of what the final version of my recommendations will be, but there is still a slight quirk or two to try to figure out.

This is what I would call normal behavior and is why I will make a recommendation on a future post about how often to clean out the pump.  Here is why.....

Front of the HoB housing, seems fine. Does not get cleaned regularly, let's take a closer look.

Spillway looks fine, there are hard water deposits on the sides, entirely normal.  Does not get cleaned often, but I would say I try to make an effort to keep this clean.

This is what the pump looked like and you can see a lot of the organics from the tank in the pump housing.  My clown pleco hangs out right here and this is very likely a result of her eating a bit of the wood and it getting pushed up the pump.  This could also be due to overfeeding.  All things to monitor for your own specific situation.

As we follow the path of the water, this is the output flow of the pump, bypass here is common due to pooling in this section.  This is NOT GOOD when it comes to the form of bypass.  If you see stuff here, you have a very clogged tidal.

This is a better shot and you can see this all over the sponge, the media, the basket, and the housing.

Ultimately, I would equate this type of issue to a filter uptaking sand. I would then go ahead and recommend that if you see this, you do need to try to figure out why.  In my case, it's from the black algae or from the wood itself.  If you have a tidal, and you do not mod the skimmer, all of this stuff often clogs the skimmer and leads to needing to disassemble the chute (more on that later) and then go ahead and clean everything out.

I went ahead and reset things, clean slate, deep clean on everything.  I put back in 2 course (blue) sponges and will continue another batch of tests and keep an eye on things.  Carbon removed and back to just running the normal media.

As a sidenote, I did end up cutting open a bag of aquaclear carbon to put into a seachem bag (the one I had was for a 110, wouldn't fit in here).  I really don't like the size and quality of the carbon they use.  I'd recommend finding something else.  I hear marineland has good carbon, but I will be opting to try to find something I can use when need be.  I just wanted to mention it, because I was really surprised at this when I cut the bag open.  If anyone has other carbon they can photo and post here I'd appreciate it. I may end up making a thread so we can compare and contrast, discuss pro and cons.

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  • 2 weeks later...

Frequently (potentially) Asked Questions

1. Is this mod actually worth doing? Which parts? Why?
Well, it is an interesting question and quite a dilemma if you have a certain perspective.  I do enjoy these filters because of their reliability and their warranty.  They do absolutely have some design issues and these things show themselves right out of the box.  There are not any "do this and it's fine" methods for this filter.  There are legitimate failures by the design team for freshwater hobbyists.  Fixing some of those failures to keep the fish in the tank alive is the main reason why this mod is worth pursuing.

2. Why are there design issues?
I cannot say why, but my best guess is that because the tidal (a bit on the nose there with the name Seachem) is designed for saltwater tanks, not fresh.  Give me a "Forest" version of this product and I think you can easily make things work a bit better.  The pumps have the GPH they do because saltwater is harder to move.  The skimmer is there for, yep saltwater.  The multiple intakes are there for a few reasons, but they do not work as well when most of the water is pulled into the pump chamber from the skimmer.

3.  What are the design issues out of the box?
"bypass" is the all-encompassing term, but the real issue is that the pump is pushing the water through a variety of holes in the filtration basket leading to the foams not actually filtering the water mechanically.  Because the foams and basket do not have tight tolerances on the design (or were designed to interfere, i.e., press fit) then you have more gaps.  The water cannot get into the basket to be filtered and goes right out back into the tank.  It is pretty basic.  What is the biggest hole?  The skimmer and the window cutout.  Where is the water going to go?  Right through those two paths.

4.  Can you do a partial mod and achieve success?  Can I just seal the skimmer and call it a day?
You can, but you will get a lot more input from the pump housing, which means you will get a lot more junk in the pump.  There is going to be a final recommendation and I do like the tier system.  If you want an "easy fix" then add some mesh to the skimmer or foam to give the fish a chance to get away from the suction.  Something like tiger barbs or discus especially need this.  A sleeping wide-body fish is just a matter of when, not if the skimmer will suck them against the filter body.

5.  Is this fix reliable?  Do you trust it?
To an extent, I can say that I have ran this mod for quite a long time.  Going back and looking at dates, the basket and skimmer was sealed in the first week of June.  It has been running for over 6 months without failing catastrophically.  The pump has been fine. There have been issues and those recommendations will be made.  I do trust that the mod can be permanent.  I do not plan to remove it and I do plan to mod all my tidals with this method.

6.  What else is left? Is this "done"?
I do have the weird intake issue where air bubbles make their way into the pump.  I did find out that you can visually see those bubbles and so I need to follow that path and find out the root cause.  I have my assumption, but I need to repeat the failure and keep an eye on the source.   Second to that, I simply need to repeat it.  I need to repeat the process, take more/better photos, and run it again for an extended period with the tidal 75 housing.  I do have two of those, will be able to run them side by side.  I do not want to call anything done with a test case of 1 or 2.  Finally, I do need to finalize the input tube mod and finalize how to mod the grate.  I have a concept, ran some tests and I'm not happy with it.  I need to order parts from Seachem, but I do have another one I can opt to mod now.  Once I can get that final detail to everyone here, then I will be "done" enough to make my final recommendations.

7.  What was the biggest surprise in the process?
Hm.  I think one of the biggest challenges was finding out that the basket itself is not tall enough to do its job.  I did not expect that.  I expected things to work better when I tried diffusing flow in the base of the filter basket by using the mech type of baffling ceramic rings.

8.  What was the biggest success of this mod?
I think the filter itself is surprisingly efficient now.  Let us say that previously I had "good filtration" mechanically speaking by performing the basic tier 1 mods.  When all is said and done, you're talking about a massive improvement to the ability of the filter itself to intake junk and filter it out.  It is a basic thing, but this filter is probably the best one on the market when it comes to mechanical filtration. I do not say that lightly, I say that after jumping from one hang on back to the next trying to get things to work well!

9.  I like the filter out of the box except the blue stuff, can I just remove the blue stuff?
YEP.  You literally just remove the dial, open the half-moon shape on the intake and add one little gloop of silicone to seal the hole for the dial.  Done.  It probably is the easiest thing to mod out.  It is blue because of seachem branding.  They want to have that blue there so you know it is a tidal.  That color is on just about all of their packaging, nets, etc.  They do have a green they like to use a lot too.... they should use it on the freshwater update!

10.  What is the goal of this? Why go through all of this?
Part of me needs to get a job doing stuff like this! But seriously, I did this because I think that the information is applicable to any HoB and I think that there are filters out there that need improvement.  I want to show you, I want to show corporations, and I really want to show Seachem / Sicce how you can fix in-line issues and improve your products.  You should be doing this. There is no excuse NOT to do some of these improvements.  Parts are actually cheaper, material costs go down, quality is improved, and the best part of the whole engineering perspective is that all I care about is the customer being happy.  Which customer?  The one buying the thing, the one making the thing, and the one assembling everything. Those are my customers.

Edited by nabokovfan87
Poor Grammar
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On 2/9/2023 at 9:29 AM, Chick-In-Of-TheSea said:

Will disassemble & clean tomorrow.  I did notice during last maintenance there was a bunch of mulm, sludge inside the box. I turkey bastered out what I could.

Yeah. That's just the sponge porosity and the intake letting things through. Even if it's very fine, it will let stuff through and that builds up on the intake tube and pump mostly.  I think it was the last series of photos I posted when I cleaned mine out. That's after a month with 3 layers of sponge. Intake is always jammed with stuff and the foams inside are always mulm black with stuff, bright blue after cleaning. you can see that layer of "muck" on the top of the chute and how thick with chunks it was from the bypass. Not great! Just an indication of time to take the HoB to the sink and check everything. No biggie. Just a sign of do that and make sure everything is ok.

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  • 2 weeks later...

It's been a weird one, but productive I think.

Last night the black corydoras were spawning, but I also did not want to interfere to fix this issue.  Overnight you can see the air building up on the surface due to the bubbles being shot out of the filter.


This is an annoyance of sorts.  As I woke up and checked on the tank what I saw was bubbles clearly shooting out of the filter and blowing into the moss near the output.  The filter would clear itself and then a few second later that air would shoot out again.  Clearly something was going on.  Air was in the filter housing and it was making it's way into the pump, into the filter box.  It was good to see this because we know where the air is, but not how to stop it.   The main reason this air showed itself was because the waterline in the tank is about 1" below the rim.  It's a bit lower than normal.  Again, easy fix, but I would like to figure out a way to purge that air.  Let's run a test and see if I can simply remove all restrictions from the input and force the air out that way.

The first thing I am trying to show here is that I do not have any intake in the tank right now.  The pipe is removed and the pump has direct access to water.  I am using two fingers to restrict flow into the filter.  This forces it to try to pull water from elsewhere (not sure where or how) and there is a bit of air getting in somehow.  I think there is a pinhole in the silicone somewhere by the skimmer, but I really cannot tell when I view it.  I would need a worm light or something to check for spots.  It's a very, very minor issue.

The crux of it is this....

If you have the water level low, and you have the intake sponge full of stuff, then you can get air bubbles in the filter housing.  When I removed the intake it did not "fix" anything.  There is air getting into the housing somehow and once the restriction is removed (and the air level is low enough) this means that if can push out that air.  There is nowhere for the air to go except through the pump. 

Think of it this way as well.  If you take a bucket or cup and try to submerge it upside down, you're going to trap air in the cup.  This is common with canisters and will be common if the design of the filter in question doesn't accommodate removing all of the air.  This isn't something ANY hob filters do.  The "best" design in terms of pump and air is very likely going to be the aqueon.  The way those are setup you have an intake tube and that directly feeds into the pump which directly goes into the pipe into the pump itself.  There isn't rectangles and air traps, it's a direct path from the tank into the pump and the air has nowhere to go but out. 

So.... the real question is, does this air damage the pump.  Can it?  I just don't know.  Some pumps are designed for air to pass through (Sicce Syncra nano) and others are not.  Most submersible pumps are not meant to "run dry".  This is also true of heaters and other equipment we commonly use in the hobby.  For those familiar with PC Hardware, watercooling, those pumps have an impeller that floats and will destroy itself if there is not water to reduce friction in the pump housing.  Similar in concept to how you use water/lubricant when you machine certain materials to reduce heat.  The water needs to be in the pump to reduce heat. 

There is an adjustment and what I would view as the "final version" in place now.  I am going to run a test without any intake skimmer on the intake pipe.  The sponge is directly around the intake and that is going to make things a lot easier to maintain as well as ensure no restriction is happening.  The "guard" is my intake sponge now. 

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  • 3 weeks later...


here is the part of my basket i have modded:


i have a 35model, and there is the area that sticks out here, that i have cut a hole into to get filtration from that too:


i will probably have to expand the hole to prevent clogging,

do you think i should cut off this part?


sorry, i know this thread is about your modding, but this is definitely on topic. (im just consulting the expert on my choices).

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On 3/12/2023 at 10:07 AM, Theplatymaster said:

do you think i should cut off this part?

I don't think it matters.  What you have is pretty good.

The main thing is using a piece of plastic to cover the "window cutout" section of the basket as well.  The water is going to go through the path of least resistance, being that cutout.



Future posts moved to the new filter testing thread:


Edited by nabokovfan87
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On 3/19/2023 at 11:01 PM, nabokovfan87 said:

The main thing is using a piece of plastic to cover the "window cutout" section of the basket as well.  The water is going to go through the path of least resistance, being that cutout.

ive been wanting to get some silicone for a while for various DIY purposes.

next time i have aquarium budget ill try to get it.

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  • 6 months later...

Bringing this topic back to life with a thought I have been having. I use a Tidal 110 for chemical and floss so I don't have to access my FX4's on my 120. The bypass up the back is the main concern for me. So my thought is, the basket seems to be the problem, has anyone tried a Tidal without the white basket? I am considering cutting some plastic pieces to create a baffle on the intake side that would allow the water to come into the filter and run straight down like the design of the basket but allow it to be the entire smaller section and leave about a 1/2-3/4 gap at the bottom for the water to be directed to the right and them up through sponge, fine and chemical. Sort of like how the AC HOB's are designed. Grabbed @nabokovfan87's picture to draw what I was thinking. The idea is similar to what you posted on a 35 but instead of using foam actually directing the water under a baffle. Thoughts?


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On 9/26/2023 at 8:15 AM, Niz said:

So my thought is, the basket seems to be the problem, has anyone tried a Tidal without the white basket?

It has been tried, but once you look towards modifying or removing the basket then you're basically looking at doing a full custom setup.  Think of it more like a hang-on sump in some fashion.  They make these for saltwater as well, a hang-on refugium setup.  The design would be similar.  Overflow in... overflow out.  The issue is all of the work to get the water down to the bottom, then just simply flows up.  On of the nice things about the tidal though is that you do have some pretty decent opportunity to modify the basket of make a custom baffle out of acrylic.  It's a "generally rectangular" shape with curves you could sand to fit fairly easily.  I would recommend using a piece of thick paper (manila folder is commonly used for templates) and then transfer that over to your flat piece of plastic. Prep the surface well with cleaners and by roughing the surface appropriately. 

Another method you could consider is using the tube itself as your guide. You can remove the chute piece entirely, which eliminates your flow adjustment.  That leads to a simple hole which you could easily add a plug, attach it to a hose, then that directs the flow right to where you want it to be. 

It is definitely possible, and it's a bit of a blank canvas for you to modify if you wanted. 

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