General Hydroponics has a chitosan product called Chi:
http://www.generalhydroponics.com/genhydro_US/chi.html
GH Chi looks pretty cheap to use compared to the stuff in those links.
ODC Colloidal Chitosan is $30/oz for .25% concentration and GH Chi is $50/gallon for 2.5% concentration.
Factoring in usage rates, the GH stuff is cheaper.But look at the suggested application rate for Chi vs. Colloidal Chitosan. Is there a difference? Am I even on the right track?