I got quite a heavy cyanobacteria culture going on a 20 long when I converted it to a planted tank and placed a 55 watt power compact over it. My cabombas were covered in the slime as was the heater. I removed the slime by throwing away the plants and cleaning the heater, did a big water change, added a whole lot more plants to take up the extra nutrients and haven't had a problem since. Regards, Dave > Cyanobacteria are not algae, but they look and act much like some types of > true green algae. They are commonly referred to as blue-green algae and > sometimes as "slime" algae. They form a very dark-green (sometimes almost > black) film that can spread out and blanket anything that doesn't get out of > its way. > > Like true green algae, cyanobacteria also bloom in response to heavy > nutrient loads, and in thriving tend to remove these excess nutrients from > solution. The important difference is that blue-green algae produce poisons > (known as cyanotoxins) that can and will kill fish and other aquatic life. > Not to cause a panic, as physical removal of the cyanobacteria mats and > regular water changes will protect most fish even in the face of an ongoing > bloom ("infection"). However, left unchecked, the poisons will accumulate > and the fish will eventually get sick and die. > > I'm not sure whether the fish die as a direct result of the toxins, or > indirectly as a result of opportunistic infections attacking weakened fish. > Probably either, depending on the age, species, and overall health of the > fish in question. I do know that fish, clearly heavily stressed and "sick" > in the presence of a heavy blue-green algae bloom, can make quite quick and > dramatic recoveries when the bulk of the algae is removed and the water is > 50-80% changed. > > One reason I felt I needed to speak up here was Bonny's statement that her > tank is brightly lit. When I think of diatoms, I think of the brown film > ("brown algae") that tends to grow in the back corners and other low light > situations rather than under bright light. I may be wrong here. Others with > more knowledge feel free to correct me. > > I do know that cyanobacteria can grow under fairly modest light, but can > also thrive in bright light, even full, direct sunlight. ------------------------------------------------------------------------- This is the apistogramma mailing list, email@example.com. For instructions on how to subscribe or unsubscribe or get help, email firstname.lastname@example.org. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!