Nitrate level.

[uyopong]

if i dose potassium nitrate to increase NO3 from 5ppm to 15 ppm, will the level NO3 drop,increase or remain the same after a few days?

[|squee|]

It'll decrease when your plants take in the nitrates for nitrogen.

[vinz]

It should drop if the plants are photosynthesising and consuming the NO3. If the plants are not, then the levels will either stay the same or increase.