When I Have A Large Community Like Below, How Do I Stabilize Waste?
I hаνе a freshwater community 55 Gallon Tank. Thе community consists οf thе following: 3 severum, 1 spotted catfish, 5 tiger barbs, 3 black tip sharks, аnԁ 1 pleco. AƖѕο tο add tο thаt two baby red ear sliders.

Good filtering, plenty of gravel vacuming and water changes.
Let the nitrate levels be your guide to how much water to change. Change as often and as much as you need to keep the level down below about 30.
I would not add turtles to the mix, very difficult to keep a tank clean with them in.
You will probably need to go to a bigger tank in the future as well.
Ian
weekly water changes about a 1/3 and like he said clean the gravel.live plants will also help with water quality and adding stress zyme once a week to help with the good bacteriahttp://www.fishandfins.co.uk/stress-zyme…http://www.epinions.com/content_62341615…
Gravel Vac once a week .. simple