can i test my sand for CaPO4 accumulation?

[Reefski's]

Can i use this sand in my current system? i have a couple trash cans full of old 2mm sand from my old system. it is long dry now.

my old system had very high PO4 levels. i never tested until i got a Hanna C200 shortly before breaking that system down. PO4 tested off the scale which goes up to 2.75 ppm.

If it is contaminated with CaPO4 can I test for that by dissolving some of the sand in HCL and testing for PO4?

if i use it in my system will it leach PO4 back into the water column?

a couple photos of the system with high PO4.

http://i93.photobucket.com/albums/l58/reefski/blueacroPocillapora.jpg

http://i93.photobucket.com/albums/l58/reefski/staghornacromother.jpg

http://i93.photobucket.com/albums/l58/reefski/Monticaporangemother.jpg

http://i93.photobucket.com/albums/l58/reefski/monticapmothergreen.jpg

http://i93.photobucket.com/albums/l58/reefski/IMG_4330.jpg


Carl

[HighlandReefer]

You could place some of the sand in fresh salt mix and let it set for a while with circulation. Then test for phosphate. I would assume if you phosphate was that high in the old tank then the phosphate attached to the sand would be quite high. Acid washing the sand will remove the outer surface of the sand, which would help.

[Randy Holmes-Farley]

It will certainly have substantial phosphate on it. I might pitch it even without testing.

If you try dissolving a bit of the surface in acid and test it for phosphate, it would be good to compare the value to the same sample before exposure, since dissolution will release some phosphate from most any sand.

OTOH, what will you do if you see a particular level of phosphate in your sand? How much is undesirable?