I change my water (50%) about every 1.5-2 weeks, and the chemistry and clarity is excellent. Temp is 75, and PH is about 7.5. 125 Gal, Planted...and all except my fast growing Pennywort is growing this brown looking algae. I see it forming on the glass after about a week and you will notice round looking bundles on the heater, some tubing, and even the ends of the sword leaves...Is it Black Algae? The bundle/balls that collect on the hoses and heater are not easy to remove...and it doesn't scrape off the leave easily or with out destroying them. I don't really want to 'bleach' the plants...but I am not sure what else to do.
I have an Fluval FX4 Filter plus a C4 HOB and a large UV sterilizer as well. Lights are on for 8.5 hours...CO2 system is on about 1.5 hours before day light cycle and off 1 hour before they go off.
Thanks for the help community...I also uploaded pictures in case this helps identify the culprit. I am honestly not sure what this is...but it is all over my plants...and on the swords over time the leaves start to decay or come apart.

I have an Fluval FX4 Filter plus a C4 HOB and a large UV sterilizer as well. Lights are on for 8.5 hours...CO2 system is on about 1.5 hours before day light cycle and off 1 hour before they go off.
Thanks for the help community...I also uploaded pictures in case this helps identify the culprit. I am honestly not sure what this is...but it is all over my plants...and on the swords over time the leaves start to decay or come apart.
