problem with green algae

How much green algae? Maintenance routine? Stocking level? Tank size? Water parameters?
 
The above information would be helpful. do you have any plants? what type of lighting? is it near a window?

Algae need only water, nutrients, and light to grow. Reducing the amount of time the light is on and scraping it with a razor blade (ONLY if it's glass. use a credit card for acrylic) and increasing water changes and reducing feeding will help the most.
 
i have a few plants. java ferns and other low light plants (i forget what they are called). Not much lighting, 40 watts i think, in a 46 gallon tank. I am reducing the amount of time the light will be on. Also, would it be ok to just feed the fish every other day?
 
Most fish will be fine with every other day feedings. Some predators, and most juvenile fish, will suffer from reduced feedings. Unless you are overfeeding, increasing water changes will be a better option, IMO. You can certainly offer less daily, but stopping a feeding all together might be more than is needed.

Still looking for answers to those initial questions though--otherwise, it's all blind guesses.
 
Do you have any algae eating fish? I'm not sure what kind of tank you've got, but - if they're appropriate tankmates for the type of fish you've got - otocinclus cats are, IMHO, second to none when it comes to keeping tanks algae-free. I almost never have to scrape algae off anything, my little guys are a 24-hour cleaning crew :D
 
AquariaCentral.com