you can mix teh two but then your fertilizer will be half as strong as you had planned .....
I would mix my fertizizer solution and then add the superthrive to it instead of to a seperate gallon of water....it will not do any harm as far as I know in fact that is how I mix them when I am using superthrive.....but I use only three or four drops of superthrive.I Just read my bottle and you are right about what the directions say. I dont remember where I got the one drop per gal at LOL
here is a link to a forum with lkots of posts oon superthrive use and doses
http://forums2.gardenweb.com/forums/...294012389.html