There isn't really an inexpensive test kit for nutrients. API is a great test kit, but it won't provide enough information for the planted aquarium. the API master test kit should be used for all aquarist that desire to test their parameters, not specific to planted tanks. For your macro and micro ferts, test kits get very expensive. I would recommend not purchasing any of these. Just use the EI method for dosing ferts, you'll be fine.