Undergravel Filter Good or Bad

Hello,
I have a 45 gallon Salt water corner tank. I have two power heads connected to an underground filter and a skilter filter. I have decided to redo my filtration system because the Skilter Filter isn't doing it's job well!! I think that the filter is just a gimmick. I bought a Fluval 404 and I also wanted a Bio-wheel cause I wasn't sure of the Canister filters ability for biological filtration. I got a Penguin 303 filter. I was planning on putting both of these filters on the tank. I heard that underground filters aren't very good cause they just hold all the waste instead of removing it. Is this true are underground filters going out of style? Should I scrap the underground filter and use the two I just bought. Would a 670 gallon turnover rate, which is the two filters combined, be too much for my tank? Also I have been using water from my science lab that I work in. It is Deionized water. Is this water O.K. is it the same as R.O. water? I think it is but am not sure. I look forward to your answers.
The shrew.

[Michel]

Welcome aboard !
You are right about the under gravel it just keeps the sh... My suggestion: go with a sand bed and add in about 50lbs of LR and if you can purchase a protein skimmer . The filter can be used as circulating pump but take out the filtering media out except the occasional carbon you may use for filtration for a couple of weeks... As for turnover it depends if you want FO or FOWLR or corals but a good standard is 15x your capacity ... Hope this helps and others will be around to tell you more...
Have fun ! I know I do

[MicroFish]

I can't stand UGFs... don't know why they are still being marketed. Actually, some people have success with them, but I'm not one of those people. LOL I *much* prefer my Penguin & Emperor Biowheel HOB filters to anything else... they actually remove the waste from the water, while the UGF just leaves it to rot. Yuck.

Sheila

[Biggen]

I can't stand UGFs... don't know why they are still being marketed

Because, well, they still sell...

Trust me, we sell stuff in our store that is absolutely hideous. We have been re-ording it for years simply because people keep coming back over and over again to buy it.

I do agree that UGF's are old news, though. Especially in a sw tank.

Thanks for your quick reply!!! I wanted to ask you about the sand bed and LR. First what is LR and do I put this on top of the sand or underneath it. You say take out the filtering media. Is that from the Bio-wheel or the Fluval for the first couple of weeks? Could you tell me why also. Does lack of media help start the biological filtration of the biowheel. I have some gravel and I forgot what it was called but it has some kind of PH buffer in it for salt water tanks to maintain a good PH of 8 or so. Could you also tell me what is FO and FOWLR. I don't plan on having any live rock or corals in the tank. Just damsels cause I have had such bad luck in the past with other fish. I might upgrade my inhabitants but not for a while.
Thanks so much
Shrew.

[Michel]

Ok sorry for the TLA ( three or two letters acronyms) LR is live rocks and if you wish to have a good marin aquarium you should have some. PH is power head and it means that it moves water around like in the ocean... If you refer to ph level the it should be around 8.2 for marine. Fo is fish only while FOWLR is fish only with live rocks no soft or hard corals ... Did I cover everything if not ask some more

[Techboy]

The ugf gives a place for the bacteri to grow and pulls the wast under no circulate
then the bacteri can eat all the wast and extra food 8O

[e-cat]

there are plenty of better living things that will eat the extra food in a SW tank, i dont think there is any reason too use them with all of the more efficent filters that are avalible.

Thanks for explaining the acronyms. What kind of sand do I use? Is this live sand? Will the sand be sucked up and lost when I use a syphon to clean the bottom. Also will the biological filter start on its own or do I need to seed it?

You say take out the filtering media. Is that from the Bio-wheel or the Fluval for the first couple of weeks? Could you tell me why also. Does lack of media help start the biological filtration of the biowheel?

[loganj]

Aragonite sand is best although you can use a silica sand. The aragonite sand will slowly dissolve and help keep your alkalinity stable. You can get live sand, but any sand you put in a tank with LR will eventually become LS.

If you go with a shallow sand bed (about 1"), you'll want to siphon it carefully. It will go through the gravel vac...or some of it will. If you go with a deep sand bed, you won't want to siphon it at all. If you do, you'll disturb the anoxic areas in the sandbed which defeats the purpose of having it.

The filter media isn't needed if you add 1.5-2lbs of LR per gallon...70-90lbs in your case. The LR is the bio filter. If you use external bio media, it will produce nitrates which you don't want in the tank. For more info, go to the "articles" link on the left side of the home page. Read the articles on curing LR and the Berlin system of reef filtration. What kind of filtration you use depends on what kind of tank you want to have.

I also recommend reading "The Concientious Marine Aquarist" by Robert M. Fenner. I have this book available at http://www.captiveraisedcorals.com/Books.htm or any online retailer that sells books should have it as well. I'd shop for the best price, but it is full of info that will help you very much.

[graz3]

If used properly under gravel filters are an excellent way of creating biological filtration. You want to create a plenum. First put the under gravel filter on the bare glass bottom. Then plug the holes where you would normally put the plastic tubing. Then use coarse crushed coral for a 1" thick bed. Then use live sand with an approx. bed thickness of 3". the water in the plenum will be starved of oxygen an benefical bacteria will grow. warning - - if not done correctly this will have a very negative effect.