I have a 50lb bag of 'Yara Liva' brand Calcium Nitrate, 'solution grade', cost $32.00. Seriously...
What it said on the bag:
N-P-K: 15.5-0-0
1% Ammoniacal Nitrogen
14.5% Nitrate
19% Calcium
This stuff does a great job of dissolving quickly, I recommend it. Use it in conjunction with Jacks Professional Hydroponic 5-12-26 soluble fertilizer for a complete nutrient feed for hydro, micros included. Cost is around $40 for 25 lbs. at your local greenhouse wholesaler, or call them:
www.jrpeters.com
Add some epsom salt for a lil mag/sulphur boost. Yeah, the very stuff sold at the drug store for $8.95 for a 10lb bag.
Save MASSIVE $$$ over the jugs of stunningly expensive water at your local hydro store! The only time you'll feel silly about using it is the first time, when you realize you now know more about what you're feeding your plants than ever before- and that it costs so drastically much less than the hydro nutes you wonder why it took you so long to get the news!
I run RDWC with lots of sites, 75 gallon capacity, and I spend LESS THAN $1.00 A NUTE CHANGE. Try that with your Advanced Canna Dutch General
Botanicare glop!