Can someone review this basic explanation of water alkalinity vs hardness and tell me if this is correctly applied to our pond management?

I found it interesting to try to understand how hardness and alkalinity measure different things, and importantly how hardness doesn't tell you which element is actually making up your hardness. Acid/base balance comes in to the equation as well.

Some of the tips (like testing your soil as well as your water) is new to me.

is the advice/rule of thumb to add 5lb of ag gypsum per acre foot to bring the hardness up 1 unit (ppm) still a good rule of thumb?

I'm researching if crayfish, scuds, and shrimp (crusty critters) would do better if I raised the calcium content (hardness) of my pond and then how that relates to alkalinity. I need to figure out an easy to use test kit for water quality tests.

I just fertilized my lawn on Saturday with a zero phosphorous, slow release nitrogen, and low percent potash fertilizer. It comes preformulated with biosolids taken from reprocessed chicken manure to help with the 'micro-nutrients'. But we had a much needed but rather heavy rain today that sent a deluge of street and lawn run off into the pond. I now have a very turbid pond and assume had more than usual nitrogen load run into the pond. I expect a massive bloom and want to stay ahead of water quality if I can. I already have more than normal floating FA mats covering about 10% of the pond ready to be raked out.

Here is the link to the short article that I found even me the novice could read.

Alkalinity and Hardness in Production Ponds