I do a 15% water change every week, pretty religiously. I dose two part, and I use a trident + Apex to keep CA and Alk in check. Over the past weeks and even months, my Mg very slowly as dropped from a pretty consistent 1250 or so, all the way down to 1165 (CA is 430, Alk is 8.62). I bought Kent Tech M Mg awhile back and started adding some here and there, but no change. I started adding quite a bit but nothing changed. I recalibrated my Trident a few weeks ago and there wasn't any correction. Any ideas? I know I'm now outside of recommended levels, so it needs to get fixed. Thanks for the help in advance!