I did a search for the MSDS and didn't come up with anything. I did find a phone number for the manufacturer, so I'll call them and ask. I don't know why they don't put ingredients on their chemicals...that really bothers me. Aren't they required to?

The filter isn't actually green...the algae is gone now thank goodness. I just want to soak it to get everything out of there that the hose can't get. Especially since this was a brand new filter before we had the algae problem. I'd like to extend its life a little.

Thanks for your response...I'll let you know what the chemical company says.