[Sharkfood]

You don't have to test for all those nutrients. Tests for micronutrients in particular are expensive, and you will be trying to test for miniscule amounts.

If you give us an idea of what kind of light you are using, and your tank size, we can give a better recomendation of how you should be fertilizing. If your light levels are fairly low, you may be able to get away with an all in one, comprehensive aquarium fertilizer of the type which is easily found in stores. If you're running high light and CO2, most of us buy dry fertilizer as mineral salts.

 

[Sharkfood]

Holes in leaves are usually a sign of low potassium.

You have quite a bit of light on that tank, so plants will need more nutrients than what the flourish bottle says to dose. Flourish is a decent source of micros, but contains little potassium or nitrogen (as your zero nitrate reading shows).

With that amount of light, you would really benefit from CO2 injection also.

 

[Sharkfood]

I misread your original post. You have zero nitrites (which is good) not nitrates. I'd say you're still likely lacking K and P though, if you're dosing flourish only.

I don't know many people who actually test for nutrients. Just make sure you add enough and don't worry about exact levels. Again, you'll be better off with CO2 at those light levels (there are some running that much light without it though).