RES Turtle aquarium filtration

[LadyRene75]

New turt  mom and new to aquariums and all that goes with it ISO help!

75 gallon tank with fx4 filter, housing 1 RES 5-6 in shell length, 3 large gold fish and 2 rubies minnows. Plus have 1 large TopFin coral bubbler and green killing machine.

What filter media should I be using and in what order? Do I need a prefilled on the intake.

Water is good for 1 week post 50% water change then starts to turn color yellowish.

TIA - Michelle

[Cory]

I'd use lots of bio rings in the fx4. The sponge on the pre filter, a lot of turtles will eat, so that may not work. I'd make sure I had an airstone in the tank. If you can build an above tank basking area, this lets you fill the tank up all the way, this allows the waste to be much more diluted and longer between water changes.

Also higher quality foods really help as turtle foods can really be full of fillers. Might try mixing in some koi foods, or frozen foods. Careful not to go too high on protein, and make sure some calcium enters it's diet as well.