Water Quality

[Dopey]

I've been getting RO water from the grocery store( I know its not the best but its all that I can afford )

Theres Chemipure in the tank (only carbon source)

This is how the water looks during a change.



Lights Off.



Lights on.



After one day it got worse



Is there any way to help this problem with out a uv sterilizer?
If there isn't where would be a good place to buy one?