Help needed. Miss calculation on Under Gravel Filter

[JnSchutz]

Hi all.

Recently I set up a new tank that was supposed to run on UGF, but I messed up, I didn't take into account that the tiny slots plus the geo fabric would prevent a good water flow throughout the power head.

More about the setup here:

Undergravel filter

Hi all, i was in a lfs not my usual lfs and i noticed they had undergravel filters for sale, something that i have'nt seen for many years. It got me wondering as i have a spare tank, would it be possible to run an undergravel filter with a small external filter, if so how would you do it...

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Here:

Journal on my new 200L low tech with Under Gravel Filter

Hello guys and gals! For a quite long time I was preparing myself to set up a new planted tank using under gravel filter (UGF), but I also wanted to try the lasagna method that I learned with Alex, from the "Fishtory, the History behind your aquarium" a YT channel that I find quite informative...

www.ukaps.org

And the realization that something was off and the attempt to fix it:

Journal on my new 200L low tech with Under Gravel Filter

Hello hello. So its been 20 days since the setup. The aquarium plants are thriving, fish are delivering their fry. The pH from day one to now went from 7,2 to 7,6. But it stopped there more than week ago. So I'm quite sure it was the boulder that I place on top of my driftwood that was slowly...

www.ukaps.org

Which didn't help, because the snails decided to take over that spot as a three star Michelin restaurant.

I'm not willing to take the tank apart to fix it, but I can find a way around it.
I think I will need to dig the plates out and make the slots wider, also I think about take the fabric out, it was a quite dumb idea to put it there in the first place I guess.

But I wanna your advice on the better way to do it, or if you may have another idea or insights on this matter.

I don't think the UGF is to blame, but my miscalculations that led to poor water flow.

Cheers
Jonni

 

[Tim Harrison]

I'm not sure there is anything you can do about it other than tear it down and start again if you want to use an UG filter. However, I wouldn't bother, I'd leave it now and hook up a canister filter.

Next time, perhaps give some thought to using grill type plates. It's how I did it back in the day.

Also. . .

I can't imagine the flow would be evenly distributed throughout the entire substrate. I think it will inevitably exploit channels of least resistance. Therefore, it's likely there will still be zones with different radox potential across the whole substrate. But it really depends on how porous the substrate is in terms of grain size and interstitial space, and how homogeneous it is.

I used UG filter plates with soil substrate and a gravel tidy to prevent clogging. I also used gravel around the edges for cosmetic reasons. I'm guessing most of the flow occurred through the gravel, for instance. But the real advantage of UG filtration is that the flow beneath the plates creates an another oxidised microzone in addition to the one at the surface.

The oxidized microzone is the very thin highly aerobic surface layer of soil that interfaces with the water column. It is of huge importance in a soil substrate tank since it supports the hive of microbial activity needed to neutralise toxic substances and unlock nutrients.

Even though the system was low-energy, the plants thrived and many extended their roots in to the void below the filter plates, where they probably absorbed nutrients hydroponically as well.

 

[Maf 2500]

You could run the under gravel filter in reverse with a small powerhead and sponge in place of (or attached to) the tube.

 

[JnSchutz]

Hello hello.

At first I'm gonna try as @Maf 2500 suggested.

I assembled it in reverse today, it has more water moving, I can only tell by the amount of hair the pump pulls when I open the air tube.

But the water movement is barely seen. It became cloudy though. So o think it is working.

@Tim Harrison, I can't run a cannister on this aquarium. I don't have the money to buy it, and if I had I would have to drill some holes on my aquarium, probably on the lids.
I did some research to find if they are noisy, but I couldn't find info about it here in Brazil.
I find a cheaper one, but it costs more than a third of my paycheck. So it is a no for me.
I guess I will eventually do the maintenance that you mention.

I will cut bigger holes on the plates that are in there and add some canva screen on top to cover the bigger holes. I find a mesh that has various holes with 2,3mmX2,3mm side by side. It is used in crochet.
It will be messy, but the way I assembled it I may have some way around and don't need to dismantle the whole thing

I tried to answer earlier, but I couldn't find the time to do so.

It will run in reverse until the parts I need for fixing it arrives. Then I will share with you how I fixed it (or tried).

Cheers Jonni

 

[JnSchutz]

Well...

The reverse flow appears to have not been successful...
The sponge I had was too dense, I need a coarser one.

Today I'm gonna try to find some perlon to wrap around the power head intake.

Cheers
Jonni