So I got excited the other day and bought Micro and Macro from GLA. I didn't really look into how much to put in of each one. So I haven't done anything yet, but looking into dosing I tested my water.
GH 9 drops on my API test kit
KH 1 drop on my API test kit
I don't know what effect my Nitrates have on my ferts, and I don't understand the difference between GH KH. Could I be doing the test wrong? It seems like a pretty simple test.
Your nitrate level seems to be high enough that you do not need to be dosing fertilizers at this point (at least not the macronutrients). Are you noticing any particular nutrient deficiencies in your plants?
GH is general hardness. This is predominantly contributed to by two cationic species, magnesium and calcium.
KH is carbonate hardness and is predominantly contributed to by the bicarbonate anion.
They are measures of two different things in the aquarium. GH is how "hard" your water is (hard vs. soft is a human conception). KH is a measure of how much buffering capacity your water has (against changes in pH).
Also do I even have enough light to use Micro/Macro?
I would not worry too much about the macronutrients, as noted above. Your likely have low light at substrate level (if you current lighting is as described in your signature).