Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Where'd the algae bloom go?

I originally posted this in Questions and Observations but maybe this is a better place.

Yesterday in my small pond (25' X 50' X 4' deep) the water was green (planktonic algae I presume), visibility about 20". Pondgrass covers about 50% of the surface (will be thinning out this week) and very little filamentous algae. Today the water is clear, visibility 4'. What happened?

In the bigger pond (1/2 acre, 6' deep) the water is still green, visibility about 22".

Since I have LMB, BG, CC and mosquito fish in both, I would like to maintain some bloom. In the larger pond I have an ongoing duckweed problem and black layer muck. I've been told adding microbes may help. I'll do that later this week. I add aerated well water at least every other day although haven't done so for a week. How will the microbes effect the aglae bloom? Should I still add them to the little pond that has cleared up?

I get a nice bloom in May each year - Secchi depth goes from my typical 2'6" down to 1'6" or 1'9". Then at the end of June, it clears back to 2'6" or so again. A week later, the newly hatched fry that ate the plankton get big enough for my poor eyes to notice.

So maybe new fry ate their way through most of your bloom. If so, you should be able to detect them.

As to maintaining it, check out the expert opinions in the fertilizer section (if you haven't already).

I'm just curious if it is normal (or healthy) to have the visibility go from 20" to more than 48" overnight without any external changes that I know of.

Now the 1/2 acre pond has cleared the same way.