If there is anyone here with large recreational pond experience could you
please comment on clearing algae?

The pond in question is 3 - 4 acres and 30' at the deepest. It has some
springs. The bottom is limestone and silt. Lotsa silt. The sides slope so
adjacent runoff goes into the pond. A field is nearby and during severe
thunderstorms there is a "river" running off the field and into the pond.

I suspect that the nitrate level is high. (Think I'll take my fish pond
testers and check the levels to see.)

Also there is little plant life. Some weeds along the east shore. Some
fish, bass, pike, sunfish etc.

The owners have asked me what they should do to clear the algae since this
is used for recreational swimming and SCUBA diving.

If I advise them to plant hardy water lily will this help? Water hyacinth
would be expensive for so large an area and in Zone 5b.

Anyone ever rig a homemade UV filter using 4' black lights protected by
glass or something like that to use on a large pond?

Thanks for all help.

Heather