drawbacks to undergravel filters and small amounts of gravel

[oldshell4481]

well about a week ago while at a friends house i was looking at his tank and he has a thin layer of gravel with a non running undergravel filter. well i decided to look and see how much fish poop was under his tank so i looked under the stand and saw something swimming around under the filter, well it turns out that his last batch of convict fry(all babies died) had two strays that decided to burrow, the only two survivors of the last batch of fry were living off fish poop under the filter, so we took the tank all apart to get to them and saved them. we decided against putting the undergravel filter plates back in so as not to have any more baby fish episodes. so if you decide to have an undergravel filter, and your fish breed DO NOT have a thin layer of gravel.

[TCTFish]

Even a thick layer of gravel will eventually do the same thing. It just takes longer to get all gunky like that. I am not a fan of UGFs at all. I say...avoid them at all costs. That gunk can not only progress disease and parasitic infestations...it can produce disease causing bacteria and allow wounds to grow fungus. A dinkly air pump driven internal corner filter with floss and carbon makes a better filter!! No kidding!!

[oldshell4481]

yep i had one i removed a long time ago. all it did was hold green water underneath it.

[Gypsyqueen]

What about having stagnant water underneath all that substrate. I have read where it's good to have airflow under there.
Just curious, and thanks for your response.
Gyp

If you MUST have an undergravel filter, I would recommend a "reverse flow" system hooked up to the output of a canister filter.

[FancyGuppyGuy]

All I use are UGF's 3 years strong and still going. If you vaccum weekly or bi weekly you have no problems. Its the person using the UGF that usually doesnt know how to take care of one. At least the UGF saved a couple fry on top of that if there was something terrible under the UGF how did those fry survive.

[Fishyfanatic]

UGF's for us have been nothing but trouble. We put it in and do everything that we're supposed to do (cleaning gravel bi-weekly, changing cartirdges like normal) and it doesn't do anything good to the tank. All it seems to do is pull stuff under it for it to just sit. I finally took the last one out of the 10 gal and it was a cruddy mess. I had to tear the entire tank down. The water was so green (under it) and full of fishy poop. I also noticed that a lot of fishy waste was being pulled into the rocks, but not all the way down. They are a waste of time and money. You're better off with a hob or canister. Technology has greatly increased since the old times of ugfs.

[FancyGuppyGuy]

When vaccuming a UGF you have to go all the way to the bottom and suck the plate too. Most HOB do not have enough BIO filtration some bio wheel filters make of for the lack of Bio flitration. Canisters can have a good amount of bio filtration with the right set up.

anyhow if theres stuff going under or gathering under your UGF you either have not enough gravel, you do not vaccum right, or you do not have enough water flow for the UGF to work correctly its as simple as that.

[FancyGuppyGuy]

UGF carbon cartridges are a gimmick that causes back flow they could cause problems.

Also putting anything that says clears the water when its cloudy will mess up a UGF.

another tip to UGF's is to have cone trumpet snails. they dig into the gravel and keep it turned over and help clear any wastes trapped into the gravel.

vaccum the gravel lightly and heavly vaccum 1/3-1/2 of the gravel weekly/bi weekly and switch sides the next time. move around plants rocks etc and get under them to prevent dead spots.

Some people even stick the vaccum or the tube down the up lift tube every so often and vaccum under the UGF.

UGF's work fine if you do the right things.

[mattrox]

I don't like UGF's because i find that plants do better without them generally. HOWEVER, before I tried growing so many plants I used UGF's for years with none of the above mentioned trouble. Occasionally, I'd pull down the tank to get and gunk out, leaving the gravel damp of course. But this was usually when I changed the theme of the tank and got all new inhabitants.

Mr. Guppyman is correct. If you clean well the gunk is kept to a minimum.

They are also very handy and economical for large numbers of small tanks (<20gal),

[Gypsyqueen]

Stupid question:
When doing a partial water change/gravel vaccum, is it a must for you to disturb the entire gravel surface? Or can u just pick a spot, burrow down to the plates, and suck out whatever comes thru the plates? Thanks!
I have several neons, and I don't want them getting lost/stuck under gravel I sweep around when vaccuming. This has happened in the past, because they fit into their surroundings so well, also I want to do what is least stressful on my fish.
Gypsy

[FancyGuppyGuy]

you need to pick out a section 1/3 or so of the gravel and burrow down and clean it good the rest you can skim the surface. Next time switch the section of the gravel. You know the tube for the vaccum?? I fill it with gravel when when the tube is full I pinch off the hose a few times to release it. If you tap the gravel it will fill up the vaccum tube easier.

[kathrynjuhl]

I use my UGF as a aeration system, I have 8 hoses that run down there, 2 are still set up filter like, 2 of them run to little chests and clams that let the bubble go and the other 4 are at each corner pointing in ward so that the water actually moves under there. I have a power filter on the side but my fish like to play in the bubbles.

[mastershake]

just out of curiosity, do most of you use the airstones and set it up that way, or do you use powerheads? and if you used powerheads is it likely that the "gunk" would be there still or would the water be moved better and that stuff removed somehow?

[FancyGuppyGuy]

I Use both powerheads and air drive larger tanks have powerheads 2-3 gallon tanks have air driven. power heads are better and get more water flowing through the gravel.