under gravel filter with pump/powerhead mod (bottom placement)

[venzi]

Hi.  So a common setup for UGFs and powerheads is to place the powerhead at the top of the uplift tube.  This is obviously a quick and convenient setup. 

However, in my 20H tank, noise and aesthetics are a concern for me.  Having the powerhead at the top of the uplift tube is not ideal for aesthetics nor noise.  Also, it seems the slowest/smallest powerhead I could find are like 100gph and higher.   But there are smaller pumps (https://www.amazon.com/dp/B086G9M568/ref=emc_b_5_t?th=1) that can do like 50gph which would theoretically be quieter.

So I was curious if anyone has tried to place the powerhead at the bottom instead (to conceal the powerhead more (perhaps even completely within the gravel) and maybe have some tubing or pipe stick out to the top.  And maybe have like a 90 or 45 degree bend at the top of the tubing to agitate the water even better than having the water go straight up.

As shown in the attached picture, I'm not sure the best way to setup the intake for the pumps.  For Pump A, would it be ok to just place the intake flat on the UGF plate?  For Pump B, would I drill a hole into the UGF plate for the intake nozzle or add some tubing/pipe that would somehow affix to the where the uplift tubes typically go (not sure how to affix it - maybe silicone caulking?).  I guess in either situation, I'm trying to understand how much of a "seal" there needs to be be in the intake to ensure good enough flow is coming from below the UGF plate and not the surrounding gravel.

 

 

[Jmhowe09]

One major drawback is when the powerhead fails, you will have to uproot your take to get it out and replace it. I would also be concerned that the power head would not have enough flow available to it under the gravel, causing it to burn up faster than usual. 

 

What if you hid the powerhead behind some plants? Some vallisneria or a quick growing plant like water sprite or water wisteria would have it hidden pretty quickly. 

[venzi]

@Jmhowe09  I didn't think about the effort involved to replace the pump!  Thank you 🙂

After thinking about it some more, I will not be attempting the Pump A (above the UGF plate placement).  With a Pump B placement, the intake would be below the UGF plate so flow should not be an issue (or at least it'd be the same amount of flow as placing the pump at the top of the uplift tube).

[Wrencher_Scott]

On 8/8/2022 at 12:03 PM, venzi said:

@Jmhowe09  I didn't think about the effort involved to replace the pump!  Thank you 🙂

After thinking about it some more, I will not be attempting the Pump A (above the UGF plate placement).  With a Pump B placement, the intake would be below the UGF plate so flow should not be an issue (or at least it'd be the same amount of flow as placing the pump at the top of the uplift tube).

I don't think any pump would fit under there anyway. Then you have to worry about gravel/sand/ect getting in it. Replacing it. 

You will have a much better filter than any HOB when you are done, that's for sure. 

[Odd Duck]

On 8/8/2022 at 2:03 PM, venzi said:

@Jmhowe09  I didn't think about the effort involved to replace the pump!  Thank you 🙂

After thinking about it some more, I will not be attempting the Pump A (above the UGF plate placement).  With a Pump B placement, the intake would be below the UGF plate so flow should not be an issue (or at least it'd be the same amount of flow as placing the pump at the top of the uplift tube).

Pump A would be very problematic, for sure, as you do need at least somewhat of a seal to pull water from under the UGF plate.  Plus the pump would be at higher risk for pulling in grit that could damage your pump.  Pump B might be difficult to use for the same reason - getting a seal between the UGF plate and the pump.  Most use powerheads connected to a softer piece of hose that connects to the plate or the uplift tube, or a pump that directly fits the uplift tube. There’s nothing wrong with putting your powerhead as low as possible as long as you get a decent seal to the plate or uplift tube.  

Many people that use powerheads with UGF’s are also looking for surface agitation to increase oxygenation.  Putting the powerhead lower would still likely give you very good oxygenation since circulation should be excellent, but would not give you super elevated oxygen levels that come from more surface agitation.  Most tanks don’t need super saturation levels, so placing it deeper in the water is sufficient as long as you don’t mind the current pushing on your plants.  The current from powerheads can be a bit too much for some plants.  That’s another reason why some put the powerheads at the top, so it doesn’t tear up the plants as much.

[Patrick_G]

I use a  system that’s similar in theory in my patio pond. The difference is the gravel and pump is in a box. Because it’s in a box I can lift it out and service the pump when it gets clogged, if it was under a plastic plate like a ugf it would be really difficult to service. 
 

On 8/8/2022 at 12:03 PM, venzi said:

With a Pump B placement, the intake would be below the UGF plate so flow should not be an issue (or at least it'd be the same amount of flow as placing the pump at the top of the uplift tube).

Quite a bit of mulm makes it’s way under the plates of an UGF. You’ll probably find the flow rate decreases over time to the point where you need to clean the plenum area and the pump intake. 

[venzi]

@Odd Duck Thanks for all your feedback.

@Patrick_G wow, a dedicated box.  There's so many tweaks that could be made to enhance ease of use and maintainability 🙂.  What'd you make the box out of?  do you have pics or a build log?

Edited August 8, 2022 by venzi

[Patrick_G]

On 8/8/2022 at 1:05 PM, venzi said:

@Odd Duck Thanks for all your feedback.

@Patrick_G wow, a dedicated box.  There's so many tweaks that could be made to enhance ease of use and maintainability 🙂.  What'd you make the box out?  do you have pics or a build log?

I think I have some pics, but It’s literally just a shallow plastic  box filled with gravel. I cut an opening in the lid and added a screen made of a 3M scrubbing pad. It was a rough and ready solution during 2020 when I had to make do with what was on hand. I’ve never replaced it because it works fine. My 100 gallon patio pond with 6 medium sized goldfish stays toxin free. 
 

I’ll look for the pics for you
 

Edited August 8, 2022 by Patrick_G

[OnlyGenusCaps]

On 8/8/2022 at 4:00 PM, Patrick_G said:

but It’s literally just a shallow plastic  box filled with gravel

When I used to build vivariums (which would now be called paludariums for some 🤬 reason), I would often hide the pump for the waterfall under a shallow layer of substrate, often gravel, encased with fiberglass window screening sandwiched between two upturned plastic strawberry baskets.  I haven't seen those little green strawberry baskets in years as they all come in clamshell packaging now, but wouldn't you know it, you can get a 48 pack on Amazon for like $20.  That allowed free flow to the pump, and made access easy when I had to clean or replace it.  Might not work in this application, but a hidden, accessible pump box can be really awesome and solve lots of problems.  

Edited August 9, 2022 by OnlyGenusCaps

[venzi]

On 8/8/2022 at 2:22 PM, OnlyGenusCaps said:

plastic strawberry baskets

lol oh yea those.   yea my brain is working over drive on all the ways I could go about solving this problem.  I'm gonna have to limit the scope for the first iteration 🙂 then try to enhance it over time.  But yea, modularity/servicability will be key.

[venzi]

On 8/8/2022 at 12:41 PM, Patrick_G said:

Quite a bit of mulm makes it’s way under the plates of an UGF. You’ll probably find the flow rate decreases over time to the point where you need to clean the plenum area and the pump intake. 

It was my understanding that it's pretty clean under the UGF plate.  But maybe this is only after the tank is seasoned?  during the months it takes to get to that point, there can be some mulm buildup on the tank bottom? 

Or are you referring to mulm that keeps circulating in the tank following the water flow path? In which case, I suppose pumps that are placed above the uplift tube would have a similar problem.  Do pumps that are placed above the uplift tube need to be cleaned periodically due to mulm buildup?

[Patrick_G]

On 8/8/2022 at 3:08 PM, venzi said:

It was my understanding that it's pretty clean under the UGF plate.  But maybe this is only after the tank is seasoned?  during the months it takes to get to that point, there can be some mulm buildup on the tank bottom? 

It’s been a long time since I ran a UGF but I remember cleaning “muck” from under the UGF area after a year or so. I’m sure I disrupted the cycle, but as a kid I was more concerned with having good flow from the uplift tubes. 

[Odd Duck]

I used to run UGF’s on nearly every tank back in the day (up to 20 tanks at a time even back then).  The only time I ever cleaned under my UGF plates was if I broke down a tank to move it or decided to change the substrate completely.  They rarely ever had more than a thin scattering of mulm underneath and that was with even fairly coarse gravel.  I usually ran fairly fine gravel (I just like the looks more plus it’s more surface area) and mostly ran air on my UGF’s except when I was running one on my 70 gallon (biggest tank I had back then).  Current UGF’s haven’t been running that long and they’ve had pretty low loads, so I’m not at all concerned about mulm build up under them. Plus I have some very helpful detritus worms in the mattens I’m running as substrate.  I’m pretty sure they will prevent much mulm from getting through the foam to get under the UGF’s.

[Patrick_G]

On 8/8/2022 at 3:59 PM, Odd Duck said:

They rarely ever had more than a thin scattering of mulm underneath and that was with even fairly coarse gravel.

Now I’m doubting my memory of my ugfs in the early 1980s. I’m sure the flow would slow down after a year or so, but maybe I’m wrong about the gunk under the plates. 12 year old me wasn’t very observant! 

[Brandon p]

There is not much room in a 20 to that. I would shorten the lift tubes. Is not going to have the power that a tall lift. Will a short tube you should be able to hide it with some plants or scape.

here are some ideas 

This is more what I was talking about

 

I also have .5 inch matter filter with high ppi. I think taking up all the space on the bottom is a waste of space. 
 

here are the filter material on top of the UGF. 

[Beardedbillygoat1975]

Pecktec has been using a canister filter hooked up to his ugf. Lots of options.

[venzi]

On 8/8/2022 at 6:19 PM, Brandon p said:

Is not going to have the power that a tall lift.

Yea. I thought about that and I agree that it would probably lose too much pressure/head if I just reused the UGF uplift tubes, which are like 1" diameter.  Since, the pumps I'm  considering use rather small outlets (would use like 1/3" diameter tubing), I'm thinking (for like the first version of this setup) I can send the tubing through the UGF lift tubes so that water flow can be roughly maintained and create enough turbulence at the water surface. I'll have to experiment with this once the pumps arrive.

I love that video where the guy connects both lift tubes into one pump.  So many options here 🙂 .  I'll prob not take that specific approach though.  I want two pumps in there for redundancy. 

[Brandon p]

Have you thought of using a shrimp tank filter. I have not tried it but thought it might be an option. A I selfish reason I want to have someone else try before me. I have no idea if this will work or anything is saw it when I was bored I not think these will as much help but ideas

 

 

 

[Odd Duck]

On 8/8/2022 at 7:37 PM, Patrick_G said:

Now I’m doubting my memory of my ugfs in the early 1980s. I’m sure the flow would slow down after a year or so, but maybe I’m wrong about the gunk under the plates. 12 year old me wasn’t very observant! 

I always vacuumed 1/4-1/3 of the gravel at every weekly water change of 25-30%.  I suspect that’s part of why I never got much mulm under my plates.

[Tanked]

UGF lift tubes are required to lift/draw the water upward through the filter on an an air driven system. As long as it is clear of the gravel, the powerhead can be any height. 

[venzi]

On 8/9/2022 at 7:36 PM, Brandon p said:

Have you thought of using a shrimp tank filter.

thanks for sharing the videos. I enjoyed watching them.  I don't think I'd want to setup a filter box that big as shown in the shrimp tanks.  I want as much space for the fish to swim in for my 20H.  Which is why hiding the pumps in the gravel and using the UGF to dual purpose the gravel as a filter is appealing for me.  Doing more with less and all that.

[venzi]

So I tried out the pump and my suspicion was correct. Using the 12" uplift tube barely gives any lift at the end of the tube.  It's like barely leaking over the top.  So I'll prob end up sending the tubing through the lift tube or figure out some system to affix the tubing to the glass somehow (without the lift tube).   

Not sure if there's like sticky pads with clips I can use underwater... Or I suppose I can just like glue the tubing to the corner of the tank w/ silicone. 

[clovenpine]

Re: self-contained undergravel filters, I love the work this guy is doing. There are several videos in a series where he tries out several different substrates, etc. 

https://youtu.be/y42h7jKyJuQ

[Brandon p]

On 8/10/2022 at 1:44 PM, venzi said:

thanks for sharing the videos. I enjoyed watching them.  I don't think I'd want to setup a filter box that big as shown in the shrimp tanks.  I want as much space for the fish to swim in for my 20H.  Which is why hiding the pumps in the gravel and using the UGF to dual purpose the gravel as a filter is appealing for me.  Doing more with less and all that.

I didn’t think so but I thought it might fit. I hope the other videos were more help. There are a lot of there.