i have a 50 watt fluorescent light on my 20g tank and i have trouble controlling algae ( only in that one tank not the other one with the same light.) it is just that green scummy stuff that clogs the glass. i put the light on a timer and i do regular water changes. i don't know what kind it is ( maybe blue-green) but it doesn't seem to hurt the fish. it grows so fast i have trouble keeping up with it! it seems it grows overnight and i have to go at the tank with a toothbrush to get it all.
i don't know if it something to do with the water of what but it is driving me insane! should i get another light or what? :-\
thanks.
First order of business in combating any sudden changes in a tank, is determining who the aggressor is, in this case, something that appears to be algae, but not necessarily.
If it is algae, it means that your nutrients levels are out of whack in favour of the algae over plants.
If it is cyano bacteria, then your water parameters are out of whack and needs to be addressed.
When you say a film. is it a beautiful rich green that is slippery to the touch and peels off rather easily from whatever it is resting upon?
Or is it more like a fuzzy smeary sort of thing that is more emerald in colour?
Either way, I would say determine this first, if it is algae, then your light is probably weak, but more likely, your micronutrients as well as some macronutrients are out of balance.
If it is cyanobacteria, then you need to do some more aggressive water changes with a view to feeding less, finding the pockets of gas in the substrate, and by hand removing as much of the slimy smelly green sheets as best as you can.
Have fun, it is all a part of finding balance in a planted tank. :)
thanks, i just did a big water change and clean, i will feed less and change the lighting.