I am a spoiled ponder, being out west. Tropical blooms into December, no ice (OK this year for a week during our 100 year freeze), and abundant sunshine, even during the winter. I am spoiled, yes.
This year, my pond has had a green oily slick for months and months. 3,500 gallons, with maybe 80 very small goldfish, ( I do not feed them), so light fish load. I did repot, with tomato spikes, my 11 pots of lilies early - one of which has bloomed (twice) this season. Could it be too much fertilizer in the water?
I have manually skimmed, and deliberately overflowed the thing many times, but the next morning - bright green cover.
I do the koi clay treatment thing, and my waterfall is a skippy type "purifalls" outfit - water is pumped into the bottom, goes through bags of scrubbies, and cascades back into my cesspool.
I have done 30% water changes per week, and sat back and done nothing for two months, to cover all options. No smell, no mosquitoes, but this constant swamp by my patio. For over five years it has just been clean and clear without hastles, so now I am beyond irritated.
Clues / suggestions / bullets welcome.
Swampmaster,
Mike