Planted Tank Guru
Join Date: Mar 2009
Location: Citrus County,Florida
What would be best for the plant uptake (imo) would be to use the raw (unfired) powder and mix it into the soil substrate then cap it.
The Fraternity of Dirt
If at first you don't succeed,,, keep kicking it
2-75g planted, 5-55g planted, 5-20g planted, 110g w/30g sump, 8-10g,
2012 update adding table top pleco pans & a 90g (Nutz)