Has anyone else had issues with api nitrate test kits going bad. I've been fighting what I thought was high nitrates. Always had high levels really red finally carried some water to lfs
and test was just a little off yellow. Went ahead and purchased some new bottles to test again when I got home. I had two sets of older bottle at home. Here is a picture of all three test making sure I went by manufacturers institutions perfectly. Left to right are new to old bottles.
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