+1 ^ on live sand.
for the dry, wash it with tap water till water in not cludy anymore. then leave it in RO/DI water over night and test for po4. change the RO/DI water with new, leave over night and test again, and use when po4 reads zero or close to zero.
usually takes me 7-10 days.
good luck.
Thats a really good idea Zucker! What kinda of filter media are you using? to do this and i will for sure use the decant instead of wasting all that water
Would allowing the sand to dry out after rinsing with tap be of any benefit or is diluting in RO/DI the only/better way?