I would use 'fox farm' because I heard it works well. But if you can't find that then I'd go for Scott's. It's affiliated with MG and what I read is that you don't want to give too much nutes if you use the Scott's because then you'll end up overdoing the nutes. And I also heard if you use Scotts or MG you don't want to add too much water. But I think as long as you mix some Scotts with blood meal and bat guono ( you got your nitrogen supplement and food) you should be all set. Maybe throw in some worm castings if you can.