Green spot algae on plant leaves of Anubis plants

[nemo14]

Hello everyone!

I have a problem with green spot algae on my plants leaves and would like to have feedback on what you think.

My phosphates levels are through the roof 5.0 mg/l and to my understanding with that kind of levels green spot algae should be non existent.  The levels are high because i dose Mono Potassium Phosphate -KH2PO4 its been about two months now tried for target of 2 to 3 ppm . just bought a new master test kit and that's when i found out that my other test kit was past due date and when i do my weekly testing everything was off (a lot). Did an 60 % water change and trying to reset all parameters. Lights are T5 ho 4x45 WATS on for 7 hours a day. Running a co2 system at 30  to 35 ppm of co2. I moved power head filters around have good water flow.

Had green spot algae on glass took a scraper and removed it all.

What would cause this to happen? Could it be that my system was out of wack because of old test kit. i still did weekly water changes of 60% and my tap water is good with new test kit.

Is there anything that i can do to remove the green spot algae of plant leaves?

Any help would be great.