Alk levels fluctuating

[JenniferL]

My alkalinity levels are never stable. They are constantly ranging from 6.7 to 8.2. If I don't dose they stay at around 6.7dkh. I can get them up if I dose but they fall back in about a few days. Last dosed on April 28 and levels were 8.2dkh.

Today my reading are
pH 8.2
alkalinity 6.72
mag 1375mg/L
calcium 420

every thing else is at 0ppm except nitrates at 5ppm. I don't test these that often anymore. Is it okay to leave my alk at this level. Everything else is at the right levels so I hate to adjust too much and have calcium drop.