Should I use an under gravel filter for my aquarium?

Question

We just bought a new 29 gallon aquarium for freshwater fish. We then bought a Maxima Air Pump, and the pet store employee told us we could get an air stone or bubble wand to connect ot the air pump. We decided instead to purchase an under gravel filter that has three uplift tubes, since that's what I used to have in an aquaruim years ago. It's what I'm familiar with. The employee looked at us funny when we went to purchase the under gravel filter. Should we not have gotten that? I'm reading online that they may not be the best.

So what's better? The under gravel filters? Or air stones? I don't really like how bubble wands look when they create a huge wall of bubbles, but I wouldn't mind just a tiny stream of bubbles in the tank. Help!

Oh boy. I'm confused haha. Ok, so we bought a Power Filter (that hangs over the edge of your tank). Does the air pump connect to the power filter? Or does the air pump provide another source of oxygen in addition to the power filter?

Sorry :) Thanks for your help.

Answer 1

Undergravel filters are probably the least efficient of all filtration methods. In principal, it's a good idea: they "suck" all the uneaten food and poop into the gravel where it can biodegrade naturally; kind of like throwing a grape on the ground to let it rot. In reality, it just doesn't work, because unless you have very, very few fish, the biological system just can't cope with the amount of waste produced by the fish; it's like throwing all your garbage into your backyard (and using it as a toilet) - it'll just keep piling up, and it won't biodegrade anywhere near quickly enough.
So UG gravels work for a while by "hiding" all the dirt, but eventually you get a bacterial explosion.

That said, the best filtration method for a tank that small is a Hang off the Back / Waterfall wilter. This strains out the particles in the water, degrades the ammonia through a process called cycling, and the activated carbon soaks up the pollutants in the water. Much more efficient, much cleaner water. You still have to do weekly water changes, of course, but that's normal.

So in your position I would return the UG filter. If you want to keep the air pump, by all means do : you can hook it up to an air stone or even an ornament. However, it will be mostly decorative, because the HOB filter should agitate the surface of the water enough, so the oxygenation provided by an air pump will not be necessary. Airstones, btw, are not filters by any means. They just make bubbles.



Edit: HOB filters do not connect to anything inside the tank. You simply hang them over the side of the tank, and the intake tube and perhaps a part of the water offshoot will dip into the tank, but that's all. In the back of it, will be the cavity for the filter media as well as the actual motor with a cord to plug in to an outlet. Simple as pie :)

Answer 2

Undergravel Aquarium Filter

Answer 3

It's a matter of what you want to do. I have them in most of my tanks. It is my only filtration in a couple of them. The tanks that I don't use the UGF, have sand for a substrate. It doesn't matter if you use one or not, you will still have to clean the gravel once in a while.

I have powerheads attached to all of them except for my 5 gallon and 55 gallon tanks. The one is just a bit small for a powerhead, and the 55 has my Angels in it.

I know I'll probably get griped at for this, but in the tanks that I have the UGF in, I personally never vacuum the gravel. I have those cone snails(don't remember what they are) in the tanks, and they do a pretty good job of keeping the gravel clean. The goldfish that I have in the tanks also help. That seems to be their favorite pastime. They love digging through and cleaning the gravel. (Yes, I know you all say that goldfish prefer cold water, but mine are the most active fish in the tanks)

If you have an UGF, you can use either the airstones, or a powerhead. It's up to you. They both do the same thing, move the water through the filter plate, and move the water throughout the tank. Bubble wands are more for decoration than anything else.

My plants do just fine with the UGF too.

Like I said before. It's just a matter of what you want to use. It won't hurt anything to have a UGF, unless you're using sand. Then it's more problem than it's worth.

Either way, it's not a bad idea to get a hang on(like the Whisper) or a canister filter also.

Answer 4

Undergravel Filter

Answer 5

Really its just a matter of what you are comfortable with or know how to use. I never use them but they DO keep your gravel cleaner. I use a Penguin bio-wheel and an airstone. But I clean the gravel once a month. Undergravel filters can cause problems with air pockets under the gravel if you're not careful. These air pockets are HUGE breeding grounds for bacteria. What ever you pick just keep the place clean....but remember there is such thing as too clean.

Answer 6

Well modern power filters do an excellent job of filtration, and they're easy to clean out. Hanging power filters both filter and aerate the tank, and are quite cost effective.

There is no doubt that undergravel filters do a great job at biological filtration, but they just collect more and more waste under the filter plates and in the long run become a great nitrate factory. and the only way to clean it out is to tear down the whole tank.

There are still advocates of UGF's, and it was pretty much THE thing to do when I first started in this hobby, but I would never go back to them, not with so many superior options out there.

Answer 7

The under gravel filter has several flaws, but also has some mis-information about it as well (so do the abilities of many over-rated HOB filters as well)

That said, the flat plate type are less desirable but all need vacuuming (which includes pulling our the lift tubes and siphoning here as well)

The good points are they are good nitrifying filters (nitrifying bacteria breaks down the dirt in the upper gravel layers, which should be no more than 3" deep)

The bad points are they tend towards organic mulm build up, are nitrate factories, and are a poor choice for planted aquariums.

I would recommend a sponge filter for your bio filtration over an under gravel filter and as an excellent compliment to your HOB filter, as in studies these often under rated filters out perform most HOB filters for bio filtration.
You can use your air pump to power this.

For MUCH more information about aquarium filters, please read this article:
http://www.americanaquariumproducts.com/Aquarium_Filtration.html

I might also add that do not use them anymore in new set ups (the flaws out weigh the benefits), but I have used many a UGF over the years in aquariums i have set up for clients (such as the Bahooka Restaurant in LA with 80 + tanks), but some of the information currently available about these filters is not from experience of using them.

Answer 8

There is nothing wrong with under gravel filters as long as you understand their limitations. Under gravels do a great job of biological filtration, a fair job of mechanical filtration and do no chemical filtration at all. On the plus side they are cheap to buy, cheap to maintain and good for aeration in the tank. They are also difficult to maintain long term and are a poor choice if you have plants or fish that dig in the gravel much at all.

After 25+ years experience with them, I totally disagree with the idea that undergravels are bad filtration. Properly used they do a fine job within their limits.

Generally speaking a hang on the back power filter is the better choice for a typical community aquarium, it's easier to maintain and does a good job at all three types of filtration. I use under gravel filters all the time, but only for special applications, for general use I rely on the power filters mentioned above.

Answer 9

I tell people that they should always use an undergravel filter in ALL aquariums. Yes even salt water tanks. Your outside filter will do good for the water only, but not the sand. The sand needs to be filtered to get rid of the nitrates that accumulate in there from the fish poop and uneaten food. YES, . . . fish poop.!
However, make sure that you get an undergravel filter unless you are not going to have any gravel or other objects on the bottom of the aquarium.
OK ?

Good luck and have fun with your fish tank. !

Answer 10

That is utter nonsense about efficiency - the purpose of an undergravel filter is to harbor the anaerobic bacteria that will break down the fish waste into less toxic forms. Filter is kind of a misnomer. If you have excessive waste then the first thing is stop feeding the fish so much - people tend to overfeed their fish and that is more of a hazard than the waste products of the fish.