Probably would be fine. Just keep in mind the three numbers don't mean the concentrations, such as 30:10:10 is the same as 3:1:1 - they both contain the same amount of ferts, it's just a ratio. You might know this but I thought I'd say it anyways just in case. I have used the Shultz before and it worked fine, but you would be better off with one made specifically for weed and make sure it has all your micro nutrients.

You might want to add 2 table spoons of dolomite lime to each gallon of soil. This will ensure your PH stays perfect - or close to it and acts as a PH buffer. I have done this and continue too as my plants stay healthier longer as the grow progresses. YOu can find it at most nurseries - just make sure you get fine powderized and not granules. Hope this helps!

TGT