Is there a rule of thumb regarding DSB sizes? I don't have one at the moment and don't want to fill my sump with sand, was thinking about adding some containers of sand and changing them every six months or so.

ALso is there anyway to clean the phospates etc out of sand/gravel, I have a bucket of coral gravel from my old tank sitting outside in the rain, it has been there for 3-4 months, was wondering if this will clean it and how long it will take, or if not if there is another way?

im thinking of doing the same thing, using a small glass tank in the sump with sand it it. i wanna be able to see a cross section of it so glass would be the one as opposed to doing it in a container. doesnt a dsb have to be at least 6 inches deep to work properly?

What purpose do you want the DSB for? If it is solely for nitrate reduction, then there's a huge thread on this at RC. Just do a search for remote deep sand bed or (RDSB).

I have one of these on my system. Basically, it's a 70 liter trash can full of sand, kept in the dark, and has "clean" water flowing over it at a relatively high rate. I have no clue whether I am getting any benefit from this or not since I changed multiple factors with the tank at the same time. However, I did have enormous amounts of HA prior to its addition and I have almost none now. I was a bit desperate at the time and willing to try any form of snake oil.

If you want the DSB for critters, etc..., then please disregard.

Cheers,

Steve

wondering how big it would have to be to get any real benefit as well, may go read that rc thread

A few years ago the wisdom of the time was that a RDSB should have a footprint at least 1/2 the size of the main display.

However just how that figure was arrived at I have no idea.

I think Joe Blogg is right you would need to evaluate just what you are wanting to achieve, and where your tank is at now. For example if it was for nitrate reduction, but your tank was already pretty low, a not too big DSB may suffice.

Getting phosphate out of sand. Phosphate actually binds onto calcium carbonate, if that's what your sand is, and is pretty hard to get off. An acid bath may dissolve it off, however most of the overseas people who manage their DSB's by changing out a section of sand periodically, chuck it & replace with new to avoid the risk. If phosphate levels are well under control in your tank you may be able to risk using some old sand, long as it can be exported faster than it can leach.

Getting phosphate out of sand. Phosphate actually binds onto calcium carbonate, if that's what your sand is, and is pretty hard to get off. An acid bath may dissolve it off, however most of the overseas people who manage their DSB's by changing out a section of sand periodically, chuck it & replace with new to avoid the risk. If phosphate levels are well under control in your tank you may be able to risk using some old sand, long as it can be exported faster than it can leach.

Thanks for all your answers. I'm not worried about cleaning sand, it is coral gravel that I have, it seems to be pretty difficult to get down here at the moment, the stuff I have in the tank at the moment (about 1cm deep average) is like lots of tiny balls all the same size and looks unnatural, I want to add the gravel back in to break it up, but not if its full of phosphates, which I'm pretty sure it will be.

Coral sand can be a bit of a phosphate trap, aragonite is better.

IMO a grain size of 1.7 mls or thereabouts is best for a remote DSB, but that is still debated.

Maybe you could put that ball stuff in the DSB & some nicer looking stuff in the tank?

I'm not worried about cleaning sand, it is coral gravel that I have, it seems to be pretty difficult to get down here at the moment

I got a large bag of coral sand (think its about 25Kg worth) from Hutt Pets for $45. Not sure about phosphates etc, I just put a handful in my filters to help buffer the water a bit in my freshwater tanks.

Not sure if thats of any help, but thought I'd mention it anyway.

The stuff I have came from the hutt pet shop, but seems to be what they are all stocking at the moment.