Marvin, and the rest,
I have posted before about Blue Green Algae, unfortunately nothing really definite about how to really kill them off:
https://forum.petpitcher.net/showthre...ght=blue+green
The last experiement I did was to cover the affected pot with dried sphagnum moss, it worked. However I have found that these algae will usually kill off small plants and specially plantlets and seedlings. Seeds will not germinate also in algae covered medium. With small plants I cannot use the dried sphagnum countermeasure because it means the sphagnum will also cover the small plants and they will die too. Let us pickup the topic about algae in that topic again if you guys want
TTFN
Arvin