Are you adding 1/4 tsp (teaspoon) or 1/4 Tbs (tablespoon). You labeled it as tsb. If you are adding 1/4 Tbs, you'd be adding ~17ppm each time, which could account for your high nitrates. You should be adding something closer to 1/4 tsp, which would only be ~5ppm each time.
Most folks try to run nitrates in the 5-20ppm range
Its tsp, I got the measuring spoons so that's not an issue.
sorry mixed up on tsp with tsb and all that stuff.
I mean tsp.
So, if I have too much nitrates, can I instead of dosing 1/4th tsp, I can do 1/8th? Whats the minimum amount of nitrate I should keep it at?