I dont believe walmart sells anything thats any good, not the one near me anyways, they have a miracle grow isle, pretty much, and that I cant endorse. You might be better off with home depot, or finding a hydro store, my hydro store has a few selections that arent that expensive. Alaska fish fert is like 10 bucks and its a nice safe organic that works good and wont burn, you use it about every 3 weeks.