My Nitrates Will Not Go Down.

[HaliHostility]

I recently added a very small turtle to my 55 gal and a slightly bigger water turtle. I've heard that turtles are bad to keep with fish but this guys really tiny so i wanted to see how he works with my nitrates before i give him to my sister.
And i added the water turtle because i heard that they're not so dangerous and dirty to keep with fish, especially if the tank is BIG and the turtle is small. But my nitrates WILL NOT GO DOWN and i don't know if it's because of the turtle or if my additive just isn't strong enough...
I use PRIME..
Here is what my waters at right now.
nitrate ppm 80-160
nitrite ppm 0-.5
GH ppm 150
Chlorine ppm 0
alkalinity 40
PH 6.2-6.8 [ i have discus's so i like to keep it acidic]
Should i ditch the little turtle or what? Because I blame him....

 

[HayzH]

pass....but water change is needed for those nitrItes x

 

[phocoena]

The only way to clear nitrates is to change the water. Unless the tank is heavily planted.

 

[Dieses Madchen]

Do a 90% wanter change (this will also clear the nitrites, which is what you need to worry about as it is above 0) and it will drop your nitrates really low as well.