My 7 month old Red Eared Slider turtle has algae growing in her tank. What is a safe way to get rid of it?

i have that problems too. the best way is to clean the tank often and less sunlight. also you can get some snail to clean the tank. avoid the algae pellets because they might harm the turtles.

"Stressed out" by fish? I suspect that something else is going on here- possibly too many fish?

A thin growth of green algae on the shell is not a health problem. If it bothers you, scrub it off with a washcloth or soft brush.

The main thing is that it shows that some cares can be imporved. The water needs more filtration, etc.

Avoid the algae pellets unless they specifically say that they are safe for turtles or frogs, etc.

Algae eating fish are nice, and rarely stress turtles, but also do not do that much about the algae. Snails can help a little as well.

It might be helpful to swing by a good care site like http://www.redearslider.com/ and see what ideas they might have.

20 gal is ok only if it is a TEMPORARY enclosure. they really need much more space than that. As previously stated, 10 gal per inch is the ideal volume of water for aquatic turtles (with half that for additional turtles in the same enclosure) In my experience there is some wiggle room in this, and maybe down to 5gal/inch could be done, however this is far from ideal. One more thing. if you have not already purchased your turtle, please think long term. Turtles can live 20 years so this is virtually a lifetime commitment. Also realize the that depending on sex a RES can get up to 12'' (or ~8'' for males). this would mean you would you would eventually need a tank in the 75-125 gallon range. also turtles are much messier than fish, so purchase a filter that is rated for half-again to double your water amount.

scrub it off some algae is good but if it gets too much scrub it off with ur ahnd or a soft sponge or soemthing

just scrub it with a green pad, and clean the water regular,