I am really happy that this spring I have not (yet) seen the forests of string algae that covered the pond bottom last year. I was literally pulling out armloads of the stuff from the time the pond thawed until late June. There’s definitely still a bloom going on, but it’s maybe a tenth of the amount seen last year. A 15-minute session with a skimmer net once or twice a week plus emptying out the skimmer basket is keeping it nearly invisible except on our waterfall.
Part of the improvement was just from the pond aging and being fully planted last summer, I’m sure, but I think a lot of it has to do with my aggressively removing leaves and sticks from the pond in fall and winter. The string algae appears to thrive on decaying biological material, and removing the dead stuff seems to keep it down to a dull roar.
Note that we have a standard Aquascape system with a skimmer and biofalls – no UV, no additional filtering, no water changes. I keep the salt level at 0.1% to keep the fish happy. The water is crystal clear (no floating algae) thanks in great measure to the pond sitting in the shade (as does the rest of the backyard).
I can’t wait to find out whether the string algae disappears completely once all the pond plants start growing and sucking up the nutrients that the algae is living on!
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[...] think I was correct in stating that aggressively removing leaves and other organic material from the bottom of the pond in fall and wint…. However, I really did leave off a step in the process in the spring, and the pond suffered a bit [...]
[...] and water hyacinth – both tropicals – are now residing on the compost heap. I found last year that a bit of work in the fall and early winter can really reduce string algae in the spring. I need to also remember that while it may be necessary, it is not sufficient: an April cleanout [...]