To revisit this thread.. I found my answer to why Hyd Lime is a much better choice than sodium carbonate.
#1., Hyd Lime adds the needed calcium and is cheap.
#2., Sodium carbonate has ZERO benefit as far as calcium addition, cost is 4 times as high and takes about 5 times longer as a buffer, pH actually dips some before coming back up to a more stable condition.
So, I guess I wonder now on my personal pond how much I really need to treat it..Or, do I need to treat it at all I guess.
Some ics has came off of the eastern 1/3 of my pond and I am shocked at the clarity. I expected it to be "clearer" but didn't expect to see bottom clearly in 4' of water. I suspect that will change with direct sunlight without ice and of course limited wave action even though the shore is complete riprap now except for an open 8' section my dock slides into and out of pond.
I see a continuous growth of FA that hasn't just disappeared under the ice so with the surrounding farm land and subsequent (low volume) run-off with fertilizers present, I "may" need to treat for Phos, or FA reduction only.
Is there such a recommendation for rates on that, Rex??