Hey UB!
What can I say, you've made a believer out of me. I'm using the following, in Fox Farms Ocean Forrest soil, with about 40% perlite:
Please comment and make suggestions. It seems to work very well, but if I can do better, I will.
Osmocote Plus
GUARANTEED ANALYSIS 15-9-12
TOTAL NITROGEN (N)**. 15.00%
8.00% Ammoniacal Nitrogen
7.00% Nitrate Nitrogen
AVAILABLE PHOSPHATE (P2O5)**. 9.00%
SOLUBLE POTASH (K2O)**. 12.00%
CALCIUM (Ca)** . 1.90%
MAGNESIUM (Mg)** . 1.40%
0.70% Water Soluble Magnesium
SULFUR (S)** . 4.00%
1.00% Combined Sulfur
BORON (B)**. 0.02%
COPPER (Cu). 0.05%
0.05% Water Soluble Copper
IRON (Fe)**. 0.45%
0.42% Water Soluble Iron
0.03% Chelated Iron
MANGANESE (Mn)**. 0.06%
0.06% Water Soluble Manganese
MOLYBDENUM (Mo)**. 0.02%
ZINC (Zn) . 0.05%
0.019% Water Soluble Zinc**
Derived from: Polymer-coated: ammonium nitrate, ammonium phosphate,
calcium phosphate, potassium sulfate, potassium nitrate, magnesium
sulfate, sodium borate, iron phosphate, iron EDTA, manganese sulfate,
sodium molybdate, zinc sulfate, copper sulfate and zinc oxide.
** The nitrogen, phosphorus, potassium, calcium, magnesium, sulfur,
boron, iron, manganese, molybdenum and zinc sources have been
coated to provide 12.7% coated slow-release nitrogen (N), 7.6%
coated slow-release available phosphate (P205 ), 10.2% coated
slow-release soluble potash (K20), 1.6% coated slow-release
calcium (Ca), 1.2% coated slow-release magnesium (Mg), 3.4%
coated slow-release sulfur (S), 0.017% coated slow-release
boron (B), 0.38% coated slow-release iron (Fe), 0.051% coated
slow-release manganese (Mn), 0.017% coated slow-release
molybdenum (Mo) and 0.016% coated slow-release zinc (Zn).