fish/turtle/brackish water questions

Question
Hello:
Would it be OK to put a betta by it's self in a 20 gallon tank? Or do they need some other fish for company?

I had turtles 30 years ago. Loved them, but keep the water clean was a real pain. No filters could handle the poop. Is there any filters today that deal with turtles?

Brackish water tanks. I have never seen a brackish water tank. We have brackish water nearby; Intercoastal waterway. I see a lot of puffer fish, sargeant majors, etc. but never seen a tank like brackish. How is it to keep?

Answer
David,
Yes, you can put the Betta in a tank all by himself. They prefer it that way. As for filters, just get one that is for a bigger tank. The bigger the filter, the more it will filter the waste. Brackish tanks are done the same as freshwater. I have a couple of brackish tanks. You just do not put as much aquarium salt as you would a full salt water tank. It's not that hard, you just have to remember that salt does not evaporate and you can easily add too much. I raise and breed the Molly fish and they do a lot better in brackish than fresh water.