I filled in my garden when I dug the main pond, so all the rain does is mess up the PH of my ponds and cause huge algae blooms.
(I've only just learned about adding lime as a buffer, which has made a huge difference)
I use Aquashade pond dye in our pond to cut down on the algae. It dyes the pond a blueish green which cuts down on the wave length of light
that promotes algae growth. The other trick I use is about 10 to 15 lbs of rocks tied up in some half inch mesh netting used in gardens and
stuffed with barley straw. This promotes a break down of the barley straw and the microbial action that helps this requires the same nutrients
that the algae needs to flourish. It robs food from the algae in breaking down the barley straw. I usually have 4 or 5 of these large mesh bags filled with
barley straw and rocks with a rope tied off at the top of the mesh bag so I can pull them in the following spring and reuse the rocks for the next year when I repeat the process.
I bought 4 bales of barley straw for this when I found a farmer that was selling bales of barley straw for $8 a bale.
Compared to many, that is a bargain price.
I use a deep skimming net attached to a extendable 15' pole that lets me skim a bunch of algae from our pond.
Without the Aquashade pond dye and the barley straw bags, I would spend much more time skimming algae from our
pond.
Our yard is about 3 and half acres, all surrounded by trees, and with the 3 bag system on my riding mower, I have quite a pile of compost.
The composted grass clippings, leaf mulch, and algae all gets added together and it works wonders in our veggie garden.
