Just used the test solution with my lamotte kit. I was amazed how acurate the kit is. I have a question though- my plants do a lot better when the range is between the 4-6 on the lamotte which would be 17-26 no3. Can this be because of a low fish load? would low NH4 make you need a higher range of n03 than the recomended 5-10? Jeff Vamos cessnabum1 at aol_com