Green algae that wouldn’t come off

[nicholasrjohnson]

Hey guys,

I was having green algae growing on the sides of the tank that neither the plecos or the snails could eat. I just used my credit card to scrape it all off. Success!

 

[AquaDaBetta]

Do you have any plants in your tank? If you do, then it must be those that are causing the algae.