Re: cyano
 

WOW 2 tangs and an angel in a 90. the sooner you transfer them the better.

going to have to watch that angel around your corals.

Steve

Beverly, do think that there is any point in trying to clean old sand? If it is indeed loaded up with PO4, just rinsing it won't solve the problem. A person would have to keep it in R/O water constantly stirring in order to have all the PO4 leach out.
IMO, old sand shouldn't be re-used - it can't clean itself as well as live rock can.
What do you think?

Mitch

Mitch, I agree with you. Old sand has PO4 leached into it's surface pores and only acid will remove it. The problem with sugar sand is an acid bath pretty much dissolves it entirely!
If sand is desired, buying a new bag is well worth the $30/bag for peace of mind.

Old sand is a relitive term, if the sand was old enuf that it was giving you problems then no it shouldent be reused as a DSB, but a good rince will be fine for a thin layer of sand. If you had no problems from your sand then rince and use away.

even new sand will contrubte to a PO4 cycle so that isn't much of a issue.

Steve

cyano
 

The sand is just over a year old and I don't think is in need of changing IMO. The only problem with feeding only dried pellets is the angel will only eat mysis. He hasn't even taken a second look at any of the corals either.

How so?

SO if only Acid will remove it then it woulden't be a problem in the tank as we don't keep are tanks acidic. PO4 is natural bound to the Calcium carbonate and can be liberated by bacteria and other means. I will try dig up that article on the PO4 cycle it is good reading.

Steve

What about the lower PH level in the anoxic area of a sandbed?
EmilyB had higher calcium levels in her tank than the new salt water with the water changes and I think that it was coming from the sandbed partially dissolving.
With the low water movement levels in a sandbed, the lower areas of the sandbed are basically sitting in a "soup" of concentrated detritus, so it can't help but equalize with it's surrounding water and become further saturated with PO4...right?
Live rock won't have that problem as long as there's sufficient water flow.

Mitch

Old sand will release PO4 with fluctuations in pH. And yes, we do keep our tanks acidic. At night my tank could be pH 8.4, but in the morning it could be pH 7.9. This is much more acidic than th enight before, and therefore caused some PO4 to leach into the tank. It may very well be re-adsorbed later in the day as the pH rises, but likely it will be availabel for algae as well. To remove PO4 entirely from rock, as we inferred for the cleaning of sand, an acid bath needs to be used to completely remove the outer carbonate layer of sand where the PO4 is laocated.
The problem is that sugar sand doesn't have much more left to it after the outer layer is gone. It just turns to muck.

Now if I add new sand to a tank laiden with PO4, sure, it will adsorb it. But if the tank is clean ond free from excess phosphate, it won't adsorb it at any apprecialble rate, and certainly I wouldn't refer to it as a "cycle" but rather a long process. You would expect this new sand to last several years, assuming you followed a strict maintanence routine for the rest of the tank.

but that is still Basic, not an acidic value. so given this we should be able to soak sand in RO water say 6.2PH over night and the outer layers should be stripped off. and there will still be plenty of sand left.

anyways I am looking for the article still but here is a baise summery some one wrote in a thread, it also talks about removal and some other issues.

"Inorganic P is food, everthing in the tank wants a peice of it, bacteria.algae/corals and so on. Elements also want to bind with it, but the binds are not as strong as the organic forms. I will ive you an example. You throw in some food, the food has inorganic P in it (as it is dead and dead=inorganic, lol) The fish swallows the food, so now the inorganic is organic as the fish is going to use some. but the fish poops, animals usually poop out 90% of what they eat and keep the balance. So now the poop becmes inorganic once more. First one on the spot is bacteria, they surround it and begin the reducing feast, So right now you have an oppertunity to remove not only the inorganic form but all that bacteria which has alot of organic P bound up inside itself. Good flow and a good skimmer (along with other types of filtration if wanted) will remove both the inorganic P poop and the organic P bacteria associated. A double win for the P reduction in your tank.
Now just to side track that example for a moment and relay it to a DSb type filter and you can see that instead of exporting it via a skimmer, the inorganic P Poop goes into the bed and is taken in by bacteria and algae to form organic P. Now that bed never gives it back, it just keeps cycling the P from say organically bound P in bacteria to Inorganic P when they die, then back to organic P when the algae sucks it up then back to Inorganic form when the algae dies. the never ending and always expanding P cycle."