Under gravel filter

[Woodunder]

Hi. Why don't people use under gravel filters anymore?
I'm thinking of setting up one in a 54 litre tank.
Is this the right or wrong thing to do?
I'm thinking no sponges or media to regularly clean.

 

[PB_Smith]

Hi. Why don't people use under gravel filters anymore?
I'm thinking of setting up one in a 54 litre tank.
Is this the right or wrong thing to do?
I'm thinking no sponges or media to regularly clean.

and that is the main reason they fell out of use, the assumption that they need no care or maintenance.

Under gravel filters are one of the best methods for achieving nitrification of waste because of the immense surface area available.
but if not maintained via using a gravel vac at each water change and then every third or fourth one putting a hose down the lift tubes to siphon out any junk under the plate, they just become detritus traps and lead to ph crashes and runaway nitrate levels.

I have always used under gravel filters as part of my filtration schema and are using them now, but they do need to be maintained on a regular and consistent basis just like any other type of filter system.

 

[Woodunder]

Hi. Do you use a power head or a pump and tube?

 

[PB_Smith]

Hi. Do you use a power head or a pump and tube?

I've used both.
powerheads tend to pull to much junk into the substrate.
I have settled on always using multiple types of filtration and cut the flow rate through the under gravel way down so it doesn't actively pull as much junk into the substrate.
Air power I find is the best for a slow flow rate.
Under gravels are a great adjunct biological filtration set-up, but I wouldn't rely on it as the sole means of filtration. You really need some other means of removing particulate matter from the water so it isn't trapped to decay in the substrate.

 

[dalto]

There is nothing wrong with using them.

There are a lot more options now than there used to be though. Some better than others.

I haven't used one since I was a kid. In part because of the reduced maintenance I find with a sand substrate.

 

[ScotJudd]

I find that a lot of plants don't like under gravel filters. If you have plants then gravel cleaning is a nightmare too, disturbing the root systems in the process.
My preference in large tanks is external canister filters, the modern ones are so easy to maintain, and I use small internal sponge filters in small or quarantine tanks.


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[PNWaquarist]

Unless UG filter technology has changed recently, they're also not compatible with sand (especially fine sand) or species that like to burrow in the sand.

That said, I echo the positives about UG filters. They are indisputably excellent at establishing a strong BB colony in one's tank. When I was a kid back in the '80s, I had a 10 gallon tank with a UG filter, a HOB filter, and anywhere from 3-5 small goldfish. I had absolutely no idea what I was doing, yet my fish that survived the first month or so managed to do OK over the long-term in that tank. I attribute that to the tank's biofilter.

 

[trennamw]

I am new and havent ever used a UGF (except in those 1.5 gallon betta tanks and I don't think that counts).

I chose not to use one because I had read they have a risk of anaerobic spots and with advances in technology, the HOB is better for beginners.


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[toddnbecka]

Before I switched to sand substrates I used UGF's in all my tanks. Best way to manage them was to run an aquaclear hob filter on one lift tube for each plate. The debris never collected under the plate, just rinsed it out of the sponges when necessary.

 

[MICEY]

I used one a long time ago but a sponge is much easier to clean, I have well water so I just rinse them out in the sink and my dyi canister is all bio (lava rock, sponge , scrubbers, with a huge sponge { 1 gal} prefilter on the intake hose) plants don't like ug filters nether do loachs or cichlids

 

[Cactuspixie]

Has anyone had experience using an under gravel filter in conjunction with a canister filter? Ie attaching the canister intake to the under gravel filter?


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[Cactuspixie]

Hi. Why don't people use under gravel filters anymore?

I'm thinking of setting up one in a 54 litre tank.

Is this the right or wrong thing to do?

I'm thinking no sponges or media to regularly clean.

Personally, I think it would be a perfectly acceptable means of filtration in such a small tank. Just gravel vac with your weekly water changes and it should be fine.


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[Mebbid]

Personally, I think it would be a perfectly acceptable means of filtration in such a small tank. Just gravel vac with your weekly water changes and it should be fine.


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The only problem is you cant vac underneath the plate. It becomes a trap and anything that gets down there, stays down there.

I'm surprised nobody has mentioned this, but ugfs are a nightmare with plants.

 

[Cactuspixie]

Before I switched to sand substrates I used UGF's in all my tanks. Best way to manage them was to run an aquaclear hob filter on one lift tube for each plate. The debris never collected under the plate, just rinsed it out of the sponges when necessary.

Oooh I missed this reply. Sounds similar to what I was thinking of with a canister instead of hob.


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[Cactuspixie]

The only problem is you cant vac underneath the plate. It becomes a trap and anything that gets down there, stays down there.

I'm surprised nobody has mentioned this, but ugfs are a nightmare with plants.

Can't you suction it out?


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[Mebbid]

Can't you suction it out?


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Not very thoroughly unless you pull the entire filter out of the tank.

 

[Cactuspixie]

I last used an UGF more than 20 years ago, and I can't remember how I powered it, much less cleaned it. Lol


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[PB_Smith]

I am new and havent ever used a UGF (except in those 1.5 gallon betta tanks and I don't think that counts).

I chose not to use one because I had read they have a risk of anaerobic spots and with advances in technology, the HOB is better for beginners.


Sent from my iPhone with three hands tied behind my back.

whomever is telling you that does not understand the dynamics going on in the tank environment.

You run a much, much greater probability of have "dead spots" in the substrate bed with fine sand/gravel as it is harder for the water to naturally migrate into those lower layers and they can quickly become anoxic and develop areas of anaerobic bacteria with the accompanying hydrogen sulfide gas.

With the constant flow of oxygenated water through the substrate bed when using an under gravel filter, such dead spots are almost non existent.
The only way it happens if you do not maintain them by using a gravel vac every time you do a water change resulting in a compacted/clogged substrate and uneven water flow through it.

IMO, HOB filters are easier, not better.

 

[PB_Smith]

The only problem is you cant vac underneath the plate. It becomes a trap and anything that gets down there, stays down there.

I'm surprised nobody has mentioned this, but ugfs are a nightmare with plants.

but if not maintained via using a gravel vac at each water change and then every third or fourth one putting a hose down the lift tubes to siphon out any junk under the plate, they just become detritus traps and lead to ph crashes and runaway nitrate levels.

and I have never had any issues with plants and UG filters.
It all depends on the substrate grain size and rate of flow through the substrate. UG filters work best with a slow or medium flow rate with a medium fine substrate.

The common bagged colored gravel most often seen in stores is too large of a grain size, and is most often the culprit when talking about muck collecting under the plate.
Fine sand such as pool filter sand is too fine and is most often the culprit when talking about "dead spots" where anaerobic bacteria grow.

 

[jrc0528]

I have a heavily planted 75gal with the UG filters, an AC110 HOB, and a canister filter. I installed the UG simply to keep some water flow through the substrate, which is about 3-4" deep in my tank. Most of my plants have very healthy roots (which somehow don't get all tangled up in the UG!) and leaves.

I'll admit due to the plants I went about 6 months without vacuuming the substrate; the only thing that happened was I ended up with a severe hair algae growth. A few weeks ago I decided it was time to clean the tank and split out the plants as I'm starting a heavily planted shrimp tank. I did a side at a time, gently removing all the plants & decorations, thoroughly vacuuming the gravel, and re-planting the desired plants.

A side tip... I used a modified UG siphon vac, mine has a small powerhead atop the vac, with the hose leading to an external sump that filters and returns the cleaned water. This setup allows me to quite thoroughly vacuum all the substrate without concern for the water level! The sump has course and fine sponge layers as well as a fairly fine felt that does the final polish. The tank water gets slightly cloudy, but my other filters take care of that in a couple hours!