No nitrates in cycled tank
I have a 20 gallon long that was setup 1/23 and finished a fishless cycle on 2/11. It is about 70-80% planted and I do 25% water changes every other week. Each week I dose potassium, phosphorous and equilibrium. It is a low tech tank with around an inch of MGOCPM capped with around an inch of black diamond blasting sand. I have 3 rummy nose tetras, 7 harlequin rasboras, 2 nerite snails and a few random hitch hiker snails.
I had nitrates, although they were always around 5-10ppm until 3/1. Now they always measure 0. I am using an API freshwater master test kit that is not expired and following the directions. Is the lack of nitrates something I should be worried about or is it expected in a planted tank? My other 2 tanks measure around 10ppm but are nowhere near as heavily planted.