Hello folks im new to the forum and was hoping for some help on whats going on with my tank. I have a long established (8+years) 45 gal. tank that for the past few months 1 of 2 things would happen after a water change. 1 the ph would plummet 1-2 days after the change which I would correct with an adjuster and it would stabilize, or 2 it gets hazy to down wright milky. The ph drop and depth of cloudiness seems to depend on the amount of water I change or how much vacuuming is done. My last change (yesterday) was approx. 40% with no vacuuming and the tank is hazy. I also notice a whitish film on the glass and even on the driftwood and substrate. When the ph drops the water will get a little hazy and the tips of the fins on some of my fish will turn white as well which all goes away once I raise the ph and it has stabilized. As for the cloudiness my fish seem fine colorful and active as usual. water parameters are fine and ive fought the urge to use clarifiers. Ive been keeping fish for the majority of my life and have never had this problem until recently. Any thoughts?