My alk and cal with other test kits test real close but the mag in the trident says 1247 and the elos test kit says 1450 the kit is older should i buy a new mag test kit or trust the trident.
I mg kit is old I would lean towards trident, putting to much trust in automation can some times be a disaster waiting to happen. I would monthly test all 3 just to make sure they are close. Not just my opinion but had trident and it can drift in readings at times.
Same here. My two tridents both read lower mag than what I measure by two other test kits. As the other poster recommends I would manually measure to confirm you tank chemistry is about where you want it. I test weekly.