CARSGALOR

Hello,

I have had fish tanks for 20+ years but this is my first plant tank and I need some advice. I am looking for top quality test kits for my plant tank. I want to test for Iron, potassium, phosphorous and I am sure there are other things I should be testing. I am currently using an AP master Freshwater test kit for KH, GH, PH (to double check my pinpoint controller) and nitrates. I have been doing allot of reading but it is very confusing. For example...a good iron test kit. One claims to test for iron but is it FE++ or FE+++? Does it matter? I have read that plants can only use FE++ and in the ferric form FE+++, the plants cannot use it so I would want a test kit that only check for FE++..Correct????

Any and all help would be greatly appreciated.
Thank you.