I'm having problems with my sand bed turning into rock. I had a minor case of this in my display - then when cleaning the new SPS frag tank (on the same system), the entire sand bed (about 3-4 weeks old) was hard as a rock. I picked up one frag and the one and inch over came up up with it. I took some sand out and vaccumed the tank, now (a week later) I get back from the swap, go to put a new piece in the LPS frag tank and same thing. The LPS tanks (about 2 months old) doesn't seem to be as affected, only a few spots here and there, all near the edge.
The LPS tank has black sand (bag of wet sand "live sand") and the SPS tank was done out of dry reef sand.
levels:
CA (Salifert) 450
KH (Salifert) 9
MG (Salifert) 1400
Nitrate (Salifert) really low, as in i couldn't see a color shift
PO4 (Hanna ULR) 0.003066 PPM
the SPS tank has pretty good flow, the LPS tank is very low flow, decent turn over.
any thoughts?
The LPS tank has black sand (bag of wet sand "live sand") and the SPS tank was done out of dry reef sand.
levels:
CA (Salifert) 450
KH (Salifert) 9
MG (Salifert) 1400
Nitrate (Salifert) really low, as in i couldn't see a color shift
PO4 (Hanna ULR) 0.003066 PPM
the SPS tank has pretty good flow, the LPS tank is very low flow, decent turn over.
any thoughts?