If you want to go hardcore, get a phosphate test, API and Seachem makes them as well as a nitrogen test. You can target nitrogen and phosphate levels that work for your tank. Stick to the recommended dosage for now though until you see how your plants react.
EDIT - I see you have small nano tests. Forget the tests. You will have to use a few drops at most.
Last edited by cprash; 11-01-2012 at 05:31 PM.
Reason: yo tanks is small