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. 

[John Collins]

On 2/21/2023 at 9:58 AM, Guppysnail said:

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. 

I've read different things about vacuuming an under gravel filter. Do you vacuum yours?

[Guppysnail]

On 7/26/2024 at 10:06 PM, John Collins said:

I've read different things about vacuuming an under gravel filter. Do you vacuum yours?

Yes I did.  I found the water clarity improved as well as nitrates reduced by vacuuming.  I have since removed all my UGFs.  Breeding so many fish I continually found babies under the plate that had grown to large to escape.  I liked my UGFs but the hassle of trying to get the babies out constantly was not worth it. 

[Sammy]

I run UGFs on all my tanks, most with 1-1/2" - 2" matten (30ppi) bottoms, and they are the cleanest,  low maintenance systems I'veever had. Airstone ( Ziss from ACO) or powerhead depends on the species in the tank. The plants I use have no problem rooting to the foam. Most powerheads are directed up towards the surface to increase aeration and decrease current. A light layer of 3-5mm gravel on some, glass beads on others. Canisters with built in UV lights are attached to the heavily stocked tanks, which most are. No deaths, ammonia spikes, no diseases and stable water for 8 years on 16 tanks, water changes are severely reduced. 

I'm a big fan of UGFs. No vacuuming substrate or rinsing filters. The biofiltration surface area is unmatched except by sump systems. I even sculpt landscapes, shrimp hides and uplift tube protection with the foam. Cycling time is reduced immensely by using squeezings from other tanks.

Penn-plax for standard tank sizes, multiple plate systems for odd sized tanks.

 

[AtomicSunfish]

I use UGF in conjunction with HOB in my 10g and 29g tanks. The gravel depth is about 2 inches. I gravel vac only lightly about once a month, but not intensively because that can deplete the populations of beneficial bacteria in the UGF (which is why I also have HOB as back up). Both are air-driven, and both are Penn-Plax. I do not use UGF with fish that dig (ie cichlids) because that can compromise the efficiency of the filter by creating bypass. With digging cichlids, I use HOB in conjunction with air-driven sponge filter instead.

[Sammy]

CPD juveniles love the UGF Tiki tank 😁

[DrDeath]

Hopping on this thread to ask further: I'm also looking to start a 40 breeder (low-tech planted) with UGF and airstone. I have a mature (2 years) 5-gal planted tank. What would be a good way to use the 5-gal to "seed" the UGF tank to mature it? Siphon off some mulm and throw it in? 

[Sammy]

[Sammy]

On 8/4/2024 at 8:35 AM, DrDeath said:

Hopping on this thread to ask further: I'm also looking to start a 40 breeder (low-tech planted) with UGF and airstone. I have a mature (2 years) 5-gal planted tank. What would be a good way to use the 5-gal to "seed" the UGF tank to mature it? Siphon off some mulm and throw it in? 

Any used filter you can grab, drop it in, give it a shake or squeeze. I even use the mulm covered gravel from other tanks. Every little bit helps. I just set up 2 5gal with UGFs and squeezed and rinsed filters from my other tanks until the water was brown... clear in 5 hours. I stir and jet-rinse (with my turkey baster) until the foam has absorbed all the mulm it can get. Full cycling time is less than 9 days - but I let them mature for 2 months anyway and trickle in mosses, stem plants and ferns. If using old/used dirt substrates, I usually dose No-Planaria to eliminate that worry. 

Patience now pays off huge later, lowers maintenance too.

[AtomicSunfish]

On 8/4/2024 at 9:35 AM, DrDeath said:

Hopping on this thread to ask further: I'm also looking to start a 40 breeder (low-tech planted) with UGF and airstone. I have a mature (2 years) 5-gal planted tank. What would be a good way to use the 5-gal to "seed" the UGF tank to mature it? Siphon off some mulm and throw it in? 

You can squeeze out the media of some other filter, like an HOB or sponge. Then just let the UGF run; it will draw down the BB into the gravel, where they will become established. This way you can accelerate this cycling process from ~8 weeks down to ~2 weeks.

[Pepere]

EasyFlow kits from the Co Op can be fitted to an easily made adapter to greatly increase flow  with UGF plates…

 

[tolstoy21]

You can also DIY a UGF.  I ran a DIY one for a few years and it did me well. 

My design (a common one found on the interwebs) didn't use plates, so no fry issues (but this wasn't a breeding tank). Vacuuming was also quite easy with this design. 

This was air driven. Cost very little to make. PVC was just dry fit, so no gluing required.

 

Edited August 4 by tolstoy21