Undergravel Filters

[OscarFan]

What exactly do underground filters do and do they work.

[Tooch]

Junk. It works like a filter, but sucks in from underneath the gravel... They get clogged, and if you don't have coarse gravel, doesn't typically work...

[Incredulous_Ed]

They are undergarvl filters and they force water dwn through the gravel and up a tube and then back in the tank.

[squirt_12]

They are undergarvl filters and they force water dwn through the gravel and up a tube and then back in the tank.
ditto.....but i wouldn't get one if thats what you are thinking.....they don't work very well and generally speaking....if you are looking for a simple filter i would just go with a HOB

[KcEE]

Cleaning and maintaining a UGF is pretty troublesome. I wouldn't bother with UGF's.

[OscarFan]

I want one in addition to a regular filter.

[squirt_12]

I want one in addition to a regular filter.
i would skip it and get a HOB

[Pr0eve]

on a fair note, it is the only thing I have ever used. but I set mine up differently
then the norm, and would only use in freshwater tanks.

this is how I set mine up.

1. put in the underground filter plastic parts.
2. hook up your up lift tubes
3. lay down 1" to 1.5" of filter fiber "can be found at petco"
4. put in about 3" of gravel.
5. use powerheads to force water movement. I use a 201 for a 20G, two 401 in a 55G a 301 in a 30G. I time the size of the tank by 10. and that will get you the GPH rate that I use..

when I have taking down old tanks, it as always been clean under the plastic parts of the UGF. and your bacteria lives in the filter fiber.

I still do a 50% gravel cleaning, and use a gravel vac that hooks up to a sink. I still use 6" air stones in the back of the tank as well.

the power heads add to water movement, you can hook up air to them to help in the de-gassing of the tank.

I think they are over looked. and with the use of the filter fiber they do a great job, and it is hard to kill your bacteria when cleaning. not saying you cant, just not as easy then say with a HOB. mine as never gotten clogged.


EDIT: fixing typos, I am the typo master. :)

[fishless]

So do you have to clean or change the fiber filter, I was thinking of the same set up but without the fiber.:12:

[Drumachine09]

Honestly, you shouldn't waste your time with an undergravel filter. By todays technology, they are rendered obsolete. Just shell out a few extra bucks for a HOB that will actually work.

[OscarFan]

What is an HOB??????

[Drumachine09]

HOB-Hang on back filter, Like an AC, penguin, or emperor.

[OscarFan]

Oh. K. Thanks.

[Incredulous_Ed]

Okay, UGFs aren't that good. They may be average mechanical and biological filters, but they impossible to keep clean, so all that crud down there will cause nitrate issues. you can keep the water cleaner and the fish healthiey with an HOB or a cannister.

[Pr0eve]

Okay, UGFs aren't that good. They may be average mechanical and biological filters, but they impossible to keep clean, so all that crud down there will cause nitrate issues. you can keep the water cleaner and the fish healthiey with an HOB or a cannister.

not to start a fight, but what crud? has I said, it as all ways been clean under my UGF using filter fiber in between the gravel and the plastic parts, so I do not understand were people get it is dirty and can cause nitrates issues, and NO I never change the filter fiber, you just make sure that when you clean the gravel you clean all the way down to the filter fiber.


but I have been also looking at going in to using an HOB..

[Demi ^_^]

I haven't experienced one, but I've heard pretty bad stories with using a UGF. I'm not and wouldn't buy that type of filter, If I were you, I would fork over a couple of extra bucks for a decent filter ^_^ I'm not saying they are terrible, but thats just what I heard :)

[Pr0eve]

with out the filter fiber your right, there crap!!! with the filter fiber your turning the whole bottom of the tank into one big filter, but the fiber is key in this.

but, atm I am testing a HOB on one of my tanks.


down side of my UGF is once there in ,,, there in


each there own, I am not here to start any fights.

I do want to move up to cans...

[Drumachine09]

not to start a fight, but what crud? has I said, it as all ways been clean under my UGF using filter fiber in between the gravel and the plastic parts, so I do not understand were people get it is dirty and can cause nitrates issues, and NO I never change the filter fiber, you just make sure that when you clean the gravel you clean all the way down to the filter fiber.


but I have been also looking at going in to using an HOB..



Seeing as your waterflow is pulled down towards the gravel, fish poop, food, and such get sucked under the plate. If there isn't adequate flow, it festers, and becomes anaerobic or aerobic bacteria. I can't remember which one it is, but its harmful, and could crash your levels.


Get a HOB. Trust me, you will not regret it.

[Incredulous_Ed]

not to start a fight, but what crud? has I said, it as all ways been clean under my UGF using filter fiber in between the gravel and the plastic parts, so I do not understand were people get it is dirty and can cause nitrates issues, and NO I never change the filter fiber, you just make sure that when you clean the gravel you clean all the way down to the filter fiber.


but I have been also looking at going in to using an HOB..


Take out the filter plate. Look at all that crud floating around.

[Pr0eve]

well as I have said mine have always been clean under there.

[Pr0eve]

Seeing as your waterflow is pulled down towards the gravel, fish poop, food, and such get sucked under the plate . If there isn't adequate flow, it festers, and becomes anaerobic or aerobic bacteria. I can't remember which one it is, but its harmful, and could crash your levels.


Get a HOB. Trust me, you will not regret it.

there is filter fiber in between the plate and the gravel, poop cant get under the plates. nothing can get under the plates, just water..


get a 10G tank and try it for 6 months.

[Drumachine09]

Thats not going to prevent every thing from getting under the plates. Even a HOB isn't 100% efficient.

The bottom line is, UGFs are obsolete. HOBs filtering capacity is exponentially greater, and more efficient.

[cocoa_pleco]

yep, UGF are obsolete, i would imagine soon large HOB's may get obsolete, most of my tanks are on canisters and fluidized bed filters and ive found them to be the most efficient filters

[Pr0eve]

well I am not going to fight over some thing so dum. but it as worked for me for many years. and when you have the fiber wall to wall, I cant see how any thing get under it. and I have not seen any thing under mine and I have been setting up my tanks like this for 13 years..


but I do think cans are a hell of a lot better.

[Pr0eve]

I am here to make friends. not lose friends..



:1luvu: :thumb:

[Pr0eve]

forget the question. I just read up on them..

[Pr0eve]

hey I hope I did not make any one mad at me??

[Fishguy2727]

How do you clean the filter fiber? If it is trapping debris (which it will) and you don't remove that debris, you end up with nitrate problems.

They WORK. Yes. But they are not the best. They are (much) harder to keep from causing problems REQUIRING weekly thorough vacuumings.

Anaerobic bacteria breakdown nitrates, a good thing. Anoxic bacteria are the ones that produce toxins. Aerobic bacteria use oxygen, the usual type in our tanks are the nitrifying bacteria.

We had an UGF at work on the 90. When I pulled it out the visibility was literally about one to two inches. That is how much debris was trapped under there. That debris over time will breakdown into nitrates, causing big nitrate spikes. That is why you want all the debris to end up in places you can easily remove it, such as HOBS, sponges, and canisters.

Most people have moved on and left UGFs behind. A few people who have been using them since they were the best thing have stuck with them. I have not heard of a single person who left them behind and then went back to them because other filters just weren't as good, not even one person.

[berkeley64]

I have a 33 g long (48x12x12), fluorescent-light tank that I want to re-boot. I had previously and successfully maintained a Tangyanikan tank for severl years with two canister filters. The biggist maintenance hassle was due to my son grabbing the intake tubes and disrupting the whole thing. Very cute, I know, but not so good for the fine coral sand. So, I have an empty tank but want something REALLY simple. I was thinking UGF (so the dude can't grab the hoses), coarse gravel, school of 20 tetras (plus pleco's or loaches), and--horror of horrors--nylon plants.

Why wouldn't the UGF, perhaps with biomedia on top, then layer of thin open-celled foam, then coarse gravel, be just like a canister filter, but IN the tank? I suppose the answer is: "just try and clean out that foam, buddy."

Thoughts?

[Pr0eve]

update to my post on here,

I have changed over to HOB, and fluidized bed filters on all my tanks...

[Pr0eve]

the thing is UGF take a lot of time to clean right, so you do not have high lvl of Rates, I still like them, but I can now see why people do not like them. it is better to get the gunk out of the tank, not just to suck it down to the bottom.

live and learn I say..