Undergravel filter questions

[Up North]

I am thinking of using an UGF in a 20 long and have a few questions on them. 

1. How's deep should the gravel be?

2. Air stone vs powered

3. Recommendations on brand

This will be a low stocked thank

Thanks

[Theplatymaster]

@Up North

1. The deeper the gravel is the more effectively it will filter the tank, its like sponge in a HOB more sponge, more filtration (that analogy has quirks but i hope you understand what i mean)

2. What stocking are you thinking, if its something like Guppies that like low flow, air stone, but if its hillstream loaches; they wont mind the extra flow.

i have no recommendations on a brand.(how many companies still make these?)

[Guppysnail]

I have ugf in almost all my tanks. I find 1 inch of gravel best. I’ve tried both more and less.

I use Ziss air stones because I have hard water and others clog in a few months. 
 

I do not use powerheads because I have gobs of bottom feeders and it sucks the food down to deep to quick. 
 

I prefer penn plax over lee’s original. Lees has a bubble at the top of the outflow that makes glugging noise that’s crazy annoying. Also the lees original is smaller holes and when I vac I can’t get any of the collected gunk under it sucked out. 
 

I would like to try a lees premium because it is a different jagged design but if it has the hump in the outflow I would order penn plax outflows. 
hope that helps. 

Edited February 21, 2023 by Guppysnail

[Sweet Fish O Mine]

1. One to one and a quarter inches above plate. With this level you can easily deep vac to the bottom, and never have issues with waste build up. Even a one inch layer of gravel offers more surface area for bacteria than almost any other filter... There's no need to add more, and doing so will be detrimental over time when it starts clogging up. I've run UGF's like this for over 10 years without teardown or issues. 

2. I prefer air because it offers plenty enough flow, aids in aeration, and like Guppy snail says, doesn't instantly suck fresh food down where fish can't get it. Power heads are fine if you get smaller adjustable units and dial them down. You also need to point the output towards the surface if you want any oxygenation benefit from them.

3. I prefer the "flat" plates like the Penn Plax and others over the slightly taller "ridged" plates like Lee's Premium or the original Undertows. They allow for lower, completely even gravel layer. The Undertows will have alternating deep and shallow rows of gravel, which makes hiding plant and decoration bases cumbersome.

 

 

 

[Up North]

@Pepere thanks for the info on running sand.  I think I will give that a try, I prefer sand to gravel.  Is pool filter coarse enough?

[Guppysnail]

On 2/21/2023 at 4:17 PM, Pepere said:

landscape cloth over

Can you send me a link to what type you use?  I’m setting another up next week and want to give this a try. 

[Tanked]

I'm using 2 lees premiums and 1 that is so old that I've forgotten the manufacturer.  I have about 1.5" of gravel and prefer powerheads. 

The powerheads provide visible proof that water is moving through the filter, provide water circulation in the entire water column and some models provide for additional aeration through a venturi.  They will also clear the water considerably faster than air powered filters. The powerheads don't rely on air bubbles to lift the water so the lift tubes can be cut to any length and the powerhead can be hidden.

On the down side, depending on fish and tank size. If the power head is too big, it will blow the fish around, causing them to hide.  I have one air driven UGF, and I find that the the air pumps are noisier, and tend to loose capacity over time. Having very hard water, The bursting bubbles on this filter tends to increase the buildup of minerals on anything near the tubes.

[BuzzDaddy21]

On 2/21/2023 at 10:49 AM, Up North said:

UGF in a 20 long

What I use is Popetpop 5.91" x 5.91" x 1.06" square grids and a 20L will take 10 hot glued together also some mess screen from Joann's or a hobby shop and the uplift tube from a Lees 1- or 2-gal filter. (This will be a slow-moving plenum that will work very well)

Good luck.

[BuzzDaddy21]

I should also add that the substrate above the plates is around 4" to 5" deep.

[Andy's Fish Den]

I haven't used a UGF in many years, but when I did I used about an inch and half (1.%") of substrate on top of the plates, all  I ever used was air power. I do remember there being powerheads that you could switch the flow direction to be reversed and would send the water down through the tubes and up the gravel. I never had one of those, or any powerhead for that matter. I have been thinking about putting a UGF in a couple of tanks when I redo them this summer, I had great plant growth with them, I would pull a bunch of jungle val out to take to fish club meetings every month, and this was before fertilizers and root tabs were talked about or used, the only fertilizer was fish poop.