Hi i recently started getting brown algae sticking to my plants and ornaments. This isn't a new tank, been running for about 3 years, it has live plants and I've never used water testing kits in all the 3 years its been running which I know is bad but······so I had a brightspark (stupid?) and bought another filter. Heard that the stingrays are good for controlling algae. Didn't take the old fluval filter out just left it in along with the new stingray. Its a 60ltr tank heavily planted and with about12 4-5cm fishes and two yamato? Shrimp. The new filter is 60ltrs and over and the fluval is 25 to 50. Should I leave both in or take out the old. Don't want to use chemicals to deal with the algae cause I'm against chemicals. PLEASE ADVICE