For those who wish to argue about sand or whatever

[Pies]

I don’t believe that anyone has said that it “can’t†be done with a SB since it obviously can, e.g. many RC TOTM and even very nice tanks by this forum’s members.

Layton has made it very clear that you can not have but not both. With comments along the lines of "You can either keep a sand bed and all the near critters that go with it or have nice coloured SPS, I know what i'd choose" etc. This is the 'attitude' that I was refuring too, an attitiude of unwillingness to accept that people who are not following the BBB (Bare Bottom Bomber) method are 'WRONG'.

I personally don’t know why the “SB people†(especially you, Pies) get so uptight. Sharing this information is really just altruistic behavior.

No arguement from me here, I have from day one said that the BBB method works, but i've also said there are many people with successfull SPS tanks who don't perscribe to Bombers thoughts on the detrimental effects of sandbed (Mr Bourneman and Jbert for example or team MM). Its being told that the non BB method for SPS isn't ideal that bugs me, because its untrue.

Benefits are arguable... A comparison that Bomber has made many times in relation to critters: If we kept our houses in the same state as many of our tanks, we would be calling the exterminator immediately to deal with the "beneficial" critters. Just as a cockroach has its place in eating the rotting food on some people's floors, these "critters" do the same for some peoples tanks. The problem is that they poo just as the fish do in our tanks. Some people claim that they like these critters for diversity, but they don't typically have cockroaches as pets along side their dogs and cats.

Thats not a particualry fair analogy. I could care less about how clean my tank was, as long as the animals that I was targeting to keep where happy and well cared for is my end goal, and for it to be aesthetically pleasing to me.

What do SPS care about sand???

Not sure they do?

Photos: Not interested in a pissing contest, but am interested. There are not many reef keepers here in NZ, and I enjoy seeing other peoples setups. Especially those using different methodologies to the ones I am using, i'm always looking at ways of improving my own tank and seeing what other people are up to appeals.

I've been called lots of things, i'll add uptight to the list.

Pies

[lduncan]

I use a sandbed because they look nice, promote a healthy macrolife environment to the benifit of the corals/fish and to reduce nutrients to promote good coral colour and growth.

This is the issue which you haven't seemed to note yet. They don't magically make all the nutrients disappear. They are good for denitrification, ie they get rid of nitrate. But to perform that task they have to be dirty, and have an oxygen gradient. Denitrificaion goes hand in hand with phosphate storage. There is no substantial equivalent of denitrification for phosphorous. Phosphorous doesn't form a gas and bubble out. It's just accumulates and cycles between various forms, some of which are inert, other which are far from inert.

In short they full up, it's a process called eutrophication, it occurs in nature in both oceans and lakes.

Phosphorous is a trouble maker in aquariums. If there is one nutrient you don't want it's phosphorous.

The reason I said that SPS and sandbeds don't mix, is because you require that the sand bed store phosphorous, and SPS are killed by phosphorous. So you're storing this stuff in your sand bed, and you have rock sitting in the sand absorbing it with corals on top. Eventually it's going to cause problems, it maybe not for a few years, but there is no avoiding the fact that the phosphorous is building up.

But if you clean you sand bed, keep it free of detritus and oxygenated, you can avoid having to rip it out once it's full.

Here's one for you Pies, Borneman has called BB tanks both sterile and unstable. Pays to check your sources, no matter who they are .

[lduncan]

... there are many people with successfull SPS tanks who don't perscribe to Bombers thoughts on the detrimental effects of sandbed (Mr Bourneman and Jbert for example or team MM).

Umm, it's not Bombers thoughts at all, it's the findings of literally hundreds of scientists.

Up until a few years ago Bomber had a DSB in his personal tank (was even TOTM on reefkeeping). If you look on RC, you'll see how and why he converted it to BB.

Layton

[Pies]

Here's one for you Pies, Borneman has called BB tanks both sterile and unstable. Pays to check your sources, no matter who they are.

I don't really understand what your are saying or insinuating? What sources? What?

Pie

[wasp]

Well I'm starting to swing more towards sand beds in that case. But silica based ones. They can after all, be vacuumed.

Your origional statement seemed to hint that to get rid of nitrate, DSB's have to be dirtier than rock.

they get rid of nitrate. But to perform that task they have to be dirty

But now it seems, to work, they don't. So as a sandbed can be vacuumed, provided phosphate bonding is not an issue, There does not appear to be a problem.

[lduncan]

Essentially yes.

[wasp]

So the argument against DSB's is they can only work if they are dirty, and now you tell us rock has to be equally dirty?

Kind of takes the sting out of the anti DSB thing doesn't it? We should also get rid of our rock, it only works if it's dirty?

Only alternative is if DSB's can also work when they are relatively not dirty

[lduncan]

Nope, not equally dirty, gravity makes sure that the sand accumulates more and more dirt, and it stays there.

Bacterial turgor makes sure rock is continually purged of it.

[wasp]

But you said DSB's only work if they are dirty.

The issue is not wether or not they can get dirty, they can. So can rock.

I dissagree with the statement they can only work if dirty.

[lduncan]

The issue is not wether or not they can get dirty, they can. So can rock.

Yip, but only rock can get rid of it. Sand beds can't, they have to defy gravity to do that... or a shift oxygen concentrations, which is what you don't want to happen.

[wasp]

Edit

[wasp]

Well I'm starting to swing more towards sand beds in that case. But silica based ones. They can after all, be vacuumed.

Your origional statement seemed to hint that to get rid of nitrate, DSB's have to be dirtier than rock.

lduncan wrote:

they get rid of nitrate. But to perform that task they have to be dirty .

But now it seems, to work, they don't. So as a sandbed can be vacuumed, provided phosphate bonding is not an issue, There does not appear to be a problem.

[lduncan]

But now it seems, to work, they don't. So as a sandbed can be vacuumed, provided phosphate bonding is not an issue, There does not appear to be a problem.

They still have to be dirty to work. If you vacuum it regularly then it stops behaving like a sand bed in terms of filtration. It won't perform denitrification. It's difficult to run a sand bed so that it will perform denitrification, yet keep it clean enough not to accumulate too much crap. By trying to keep it cleanish (for example vacuuming portions after allowing a significant oxygen gradient to build up), you upset the oxygen gradient, which results in the release of nutrients tried up in the large biomass of bacteria living in the bed.

I plan to run a shallow sand bed in my next tank, vaccumed regularly to avoid the oxygen gradients and dirt which cause the problems. (as well as strategically place closed loops under the rocks to avoid crap building up under them)

I don't think phosphate chemically bonding to carbonate sand is too much of an issue, it's always going to happen on live rock and corals to some extent. It's the bacterial process which have the potential to cause the most trouble. Also silica sand is going to be harder to keep clean than carbonate sand because it is so fine, it doesn't look as nice either.

[wasp]

They still have to be dirty to work.

But no more dirty than rock, right?

By trying to keep it cleanish (for example vacuuming portions after allowing a significant oxygen gradient to build up), you upset the oxygen gradient, which results in the release of nutrients tried up in the large biomass of bacteria living in the bed.

When I had a DSB I followed Dr. Rons idea that you never touch it. Eventually realised that was unworkable in the long term and began vacuuming it. Best I could tell, after a vacuum, the oxygen gradient was heading back towards normal within hours, and denitrification fully restored in around 3 days. By vacuuming in alternate sections, I was able to achieve stable water quality throughout.

Bottom line, I do not believe a sand bed has to be more dirty than the rock, to work.

[lduncan]

But no more dirty than rock, right?

It gets more dirty than rock because of gravity. It doesn't have to be more dirty to work, but just by the nature of where it is, it does get more dirty. It's hard to avoid the effects of gravity and have sand stay in one place.

When I had a DSB I followed Dr. Rons idea that you never touch it.

You can hear how Dr Ron thinks DSB's should be run now. Only US$175 for the course, then you'll also need his books dedicated to how to run a sand bed. I wonder what's changed since the days of "never touch it"? And then you can see what a few hundred other scientists have observed, and see that it is quite different to what Dr Ron says.

Bottom line, I do not believe a sand bed has to be more dirty than the rock, to work.

That's true, but the fact is that sand can't shed the crap, away from itself. The same process which allows rock to shed (clean themselves), is the one which means sand fills up, to become more dirty than rock - gravity.

Whether it needs to be more dirty than rock is irrelevant, the fact is, is that it WILL become more dirty by way of where it is located.

Layton

[wasp]

It doesn't have to be more dirty to work

Layton

Bingo!

[lduncan]

Feel free to ignore the rest of that post. It's not important. It's just the reason why sand beds do what they do, and how they differ from rock.

Anyone heard of the Smithsonian scrubber tank?

or the GBR Aquarium?

Ueno Aquarium?

Adey?

[Feelers]

So still vaguely on the sand topic has anyone here used a fluidized bed filter? I'm asking again because of the torrent of sandbed discussion my original question drowned in

Has anyone had any experience with them?

And what would happen if you put sand in the skimmer reaction chamber? I know it's crazy - a fluidized bed protein skimmer. I might give it a jam when my tank is up and running. I spose the problem is having the sand go down the outake.

[lduncan]

I think they are used a lot in aquaculture (of fish, not coral) because of the high bioloads, they need capacity to oxidise a lot of ammonia.

[lduncan]

Found this site, full of useful information:

http://www.ozestuaries.org/indicators/I ... nts_f.html

http://www.ozestuaries.org/indicators/I ... ion_f.html

Effectively tells you the details of what's going on in sediments and sand beds. Very comprehensive with links to definitions and additional information.

Layton