I have RedSea Reefer 350 75gal. LPS tank, 2 years old system, the last two months alkalinity has been rising on its own, without dosing. I have a three-component dosage. Parameters CA-420, MG-1420, PH-8. NO3 10-25. PO4-0.1 alkalinity was always 8.3-8.6, but the last two months it began to rise to 11.6. I started changing the water Tropic Marin, they brought it down to 9.6, but then again to 11. I add KZ LPS 4 mg, KZ coral buster 4 mg, KZ flatwormstop, KZ meerwasser complex every day, all 4 mg. I read threads about increasing kh and the effects of nitrates, tried almost everything, nothing helped, also about the effects of sand. I gradually changed the sand, I don't know what to do anymore, the corals seem to be doing fine. I haven't lost anyone yet.