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Hello. I have had my turtle for 10 years and have never seen this. It looks like a gas or algae is on top of the water and it swirls in the waves. I cleaned the aquarium and it is still there. What is this and how do I get rid of it? My turtle is slightly lethargic, but otherwise fine. This has been in the aquarium for 5 days.

Details:
I got a new light that is dimmer about a month ago. I also got a new filter about 3 weeks ago.
Water parameters
GH 10
KH 40
PH 6.5
NO2 0
N03 10

Can anyone identify this?
Thanks for your help.

I figured it out. It's biofilm and is harmless. I need more water movment.
Thank you!

How big is your tank? Surface agitation is also good for the bio media in your filter.