okay I emailed general hydroponics, advanced
nutrients, and dyna-gro and I will post the answers when I get them.
I have received this from Dyna-Grow:
Dyna-Grow: The Nutrition Solution®
Welcome Conrad,
As far as I know no one uses sodium bisulfate for lowering pH in agricultural situations except for very minor adjustments. The primary reason it is not used is that sodium at medium to high concentrations in the
nutrient water is "toxic" to the plants. Some sodium is needed for plant health but as the sodium levels rise, the sodium competes with other cations, especially potassium which is very much needed in plants for a number of processes.So generally, sodium is not something you want to add in great quantity to nutrient waters.
The bisulfate certainly lowers pH and is fairly easy to handle compared to sulfuric acid for pH adjustments but again too much is not good. Other acids work just as well and don't have the sodium or sulfate problems that the sodium bisulfate has, although a little bit is ok. As you mentioned, there are many uses of sodium bisulfate for pH adjustments in the food and many industries, but not much in ag.
From the fertilizer standpoint at low total concentrations there is little affect on the solutions until you reach a point of solubility with the sulfate say with calcium, but with plant uptake the interference comes from the competition between the potassium and sodium in the plant system itself.
Sincerely,
James I. Cronin, Ph.DO., Sales Specialist
Dyna-Grow: The Nutrition Solution®
2775 Giant Rd.
Richmond, CA 94806
Phone: 510 233-0254
Toll Free: 800 396-2476
Fax: 510 233-0198
Jim@dyne-grow.com