01-19-2011, 07:05 PM
| || |
All algae (except diatoms) is caused by light with nutrients present. I'm assuming there are no live plants in this tank; they would significantly help in keeping algae within reasonable limits, because they out-compete it for light and nutrients.
A blackout will do no harm; it could only be detrimental to live plants that need light. But understand that once the light returns, so will algae since the nutrients will be there and nothing will be around to deal with them. A better method is to eliminate or in this case reduce the cause. I do not recommend any chemical preparations; these can cause more trouble than the algae is because any chemical will have a detrimental impact on fish. In a closed system like an aquarium, substances should never be introduced unless absolutely needed such as to treat disease. The fish cannot escape from anything that enters the water, so the less that does, the better.
You mentioned "green water" which is one specific issue, and you also mention scraping algae from items, which suggests another very different type of algae. The cause is really the same, nutrients in the presence of light.
I would increase the volume of your water changes. Livebearers produce quite an impact on the bioload, and plecos are notorious for doing this big time. In a 10g tank there is not much space and the water will readily become saturated. A 50% water change weekly will do no harm, it should help to reduce the organics. You have already reduced the light, but even less won't hurt. Fish don't need lights at all, the daylight in the room is sufficient for them, so using the tank light when you are most likely to view the aquarium is OK. Always make sure there is good light in the room when the tank light comes on and goes off, to avoid shocking the fish with sudden light changes that can be very stressful.