Makes sense on the calcium. I do want to be thoughtful about making a change to the pond chemistry and understand the likely consequences.

The pond is about 30 years old, 3/4 acre, and farily deep throughout with steep banks 7-11 ft. It is 100% runoff through a forested area of deciduous trees with a few pine. GIven the runoff being filtered through the forest there is little silting, but plenty of muck from leaves, branches, etc.

If I up the alkalinity, will I likely be fighting blooms that are not beneficial?