I've been reading about meters, three to be exact. PPM meter, TDS meter, EC meter, Witch one will be the best for a new grower? The PPM meter gave me a couple of numbers to go by- 400-1000, Is this right, do I keep my PPM's within that range? I also read that the TDS is almost the same as a PPM meter. I have never used either of them. So if you guys could give me your 2 cents, it would really would be appreciated. Thank-You