I'd definately recommend gettin a TDS meter first off. I made that mistake first time and lost six plants, a wise investment. Don't waste your money on a PH meter, you can get a PH test kit with a vial and test solution for like 15 bucks and they work just fine. I think a PH pen costs like 85 bucks. I've never used the powdered stuff, but the flora nova nutes are great. :thumbsup: