I have two water turtles, believed to be yellow-bellied sliders or mobile/florida cooters. They're about 9 years old and i bought them a Rena Filstar XP2 last November. It has worked great, until now when i've started to notice when you look at the surface of the water it has a blueish tint to it. When they move the water it swirls like when oil mixes with water on the ground on a rainy day but with just blue coloring. Also a little bit of brown algae has been building up in the corners on the end where the filtered water goes back into the tank. I'm not using any water conditioners or treatments, but in the filter i do have 2 small bags of ammo carb i had from my last filter. What is this and could it be harmful?


