Undergravel filters (Gasp, yes I actually said it)

[tinyfish]

I have read many posts on this board regarding the discontinuation of using an undergravel filter. I would like someone who has an exceptional use of the English language and experience (who has in the past used an undergravel filter) to explain about how the detritus (waste) creates a toxic environment (nitrate factory).
Several people are incorrect about where bacteria grows. If someone had always used an undergravel and removed it after several years one would notice a minimal amount of waste under the plastic. Bacteria eats the waste in the gravel the same as it does in a septic tank.
Suggested points in discussion:
1) Can't vacuum sand
2) Waste cycle converts to nitrate (water change gets rid of nitrate)
3) Live Rock works better (explain how it is better without massive circulation)
4) Companies really want us to buy 10 other things to accomplish pristine water.
As far as being outdated, bioballs were all the rage several years ago. The concept remains the same. Water passes over or through a media where the bacteria grow and eat the waste. The bacteria then give off or convert the waste and that is what we all want to minimize.
Last time I did salt was 30 years ago, yes 30 years.
I have however continued to do fresh water for 30 years with an undergravel and would not change. The water stays clear and I vacuum the gravel once per month. The fish are happy and I am happy.

 

[hot883]

My biggest factor is crushed coral has to be used with an underground filter because the live sand would sift through. CC gets nasty looking and is not very attractive. The cc can be vacumned but UNLIKE a freshwater set up, salt systems actually have living micro fauna, shrimps, pods, etc. that would get sucked up if you try the vacumn. I have used both and will NEVER again use the U.G. filter.
Everyone has their own opinions, thats mine.
Welcome back to the world of salt by the way. Barry

 

[phishface]

Hey tiny, the last time I did salt it was the same way. I cant tell you what you want to hear, other than I got back into it last year, the new way, and it seems to be working. But I think skimming has alot to do with it, as well as LR. But my bleached coral used to get covered in alge like the LR does now. Its full of hitchhikers, some ppl say good, others bad. I have a fish only, and run hyposalinity, works for me. Why dont you set it up, just like you did 30 years ago? Keep me informed on how it goes. C'mon prove these whippersnappers a thing or two.

 

[jasonmarc]

Hi Tiny,
I can't post and disagree with you, but I thought I'd throw in my 2 cents. I set up a FO about 2-3 months ago getting back to a tank after about 15 years. Before I knew it was a sin, I put an UGF in the tank and fired it up along with a canister filter - hell - it worked for me a couple of decades ago, so it would work again right?
My levels are A=0, Nitrite=0, nitrate=(between 5 & 10). Haven't done a water change yet. Dont' even have live rock - it's all fake.
I guess the question I have would piggy-back yours - if you have good flow through the substrate (that is, powerhead on the UGF) how would that function any differently regarding bacteria and waste breakdown than if it were just a sandbed on the glass? If anything, wouldn't waterflow through the substrate be better? I understand the concern of sand clogging the plate. I have a plate with actually quite small holes, and use aragonite as the substrate. I haven't had a problem with clogging.
I'm not sure how having waste breakdown in just a sandbed (or whatever base substance is being used) would cause less of a nitrate spike than with an UGF.
Seriously - someone explain what I'm missing?
Jason

 

[my way]

My opinions,
1} The whole idea of sand over CC, the detritus does'nt fall between the gaps as it does CC. You do neep an appropriate amount of flow to keep it suspended to be tapped by the filter, the remaining is easily accessed by your Clean-Up Crew.
2} I'm not sure I understand the question. From what I think you are asking, the less left to decay the less that is converte to Nitrate.
3}It hold bacteria just kile any other filter media, but deep inside it there is no flow so anaerobic bacteria can help convert nitrates.
4} Everyone wants to make a buck.
I too returned to SW after about a 25 yr. layoff, a lot has changed for the better, in fact the only thing bad about the hobby other than prices ( but what is'nt more expensive after 25 yrs.?) is that Elegance corals, which were easy to keep back in the day, are now hard to keep in captivity.
I never did like UG filters, even reverse flow they are detritus traps. After my first SW tank I started building my own W/D filters. I now like most people rely on LR, LS and a Refugium.

 

[my way]

My opinions,
1} The whole idea of sand over CC, the detritus does'nt fall between the gaps as it does CC. You do need an appropriate amount of flow to keep it suspended to be trapped by the filter, the remaining is easily accessed by your Clean-Up Crew.
2} I'm not sure I understand the question. From what I think you are asking, the less left to decay the less that is converted to Nitrate.
3}It holds bacteria just like any other filter media, but deep inside it there is no flow, so anaerobic bacteria can help convert nitrates.
4} Everyone wants to make a buck.
I too returned to SW after about a 25 yr. layoff, a lot has changed for the better, in fact the only thing bad about the hobby other than prices ( but what is'nt more expensive after 25 yrs.?) is that Elegance corals, which were easy to keep back in the day, are now hard to keep in captivity.
I never did like UG filters, even reverse flow they are detritus traps. After my first SW tank I started building my own W/D filters. I now, like most people rely on LR, LS and a Refugium.

 

[turningtim]

Here the way I see it, I could be wrong. I have been keeping fish for 25 years. I used to use a UGF with my FW tanks and then the last couple cichlid tanks I used an Under gravel jet system.
Useing a UGF forces waste into the substrate rather then keeping it aloft in the water colum. In a SW tank any amount of trate is not really OK. The idea is to have the waste availible for the skimmer/filter to catch the waste before it has a chance to break down.
I would have to disagree on the point that there is little waste under a UGF. When I have ever taken a tank down the bottom is always a mess and has more than likly caused issues after several years.
Sand IMHO is much less likly to allow waste to get in to the substrate and possibly cause problems. If you use CC it must be vacummed reguardless if a UGF is in place or not. Sand just doesn't catch the nastiness that CC does.
The other thing is that with a tank full or practily full of rock you can not clean the CC well enough and you will have dead spots in the UGF.
A shallow sand bed just seems to be a lot less maintenance. You just don't have to do anything to it but let sand sifters do the maintenance for you.
I'm not saying that a UGF will blow up your tank but why take the chance with something that is such a pain in the butt to deal with when something goes wrong.
Use the power heads for added flow and let the skimmer do its job. There is no comparison between a good skimmer and a UGF. Not even close!
On my 55 all I have is a skimmer and a HOB filter that I run Carbon and phos-ban in every now and then. No mechanical filtration at all. I have a 2" sand bed and about 50lbs of LR. I keep LPS, Softies and couple of fish. Its been running like this for almost 2 years and trate has never gotten over 10. Usually less then 5.
Will it work yes but why use something that is just not nessasary. As far as gadgets go, that what they are gadgets. If you set up a tank in a more natural filtration method good results can be had and don't over load your system.
Just my 2 cents
Tim