[StirCrazy]

Originally Posted by reef_raf

. At night my tank could be pH 8.4, but in the morning it could be pH 7.9. .

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."