Hey, all! This is my first post here! So, I've done some research on algae during grows. Some people say it's harmless and some say it saps nutrients from the soil and/or spreads to roots and chokes them. But, all of the examples I found were on the planting media itself and not a grow bag. Obviously the reason the algae is growing is from water, but I'm not over watering. I only water every 2 - 3 days. However, the bags are 25 gallons so the top dries out way sooner than the bottom where the algae is growing. My question is whether or not I should do anything? Has anyone encountered this before? Should I spray some sort of mold control on the bags? Should I water even less and risk wilting my plants although we've been having 100° days here? Should I just leave it? Thank you!
I don't see any real cause for concern yet unless the algae continue spreading at a rapid rate. Far as I know from even the most basic of gardening (including regular plants) algae does not do any harm, zapping nutrients would count as harming them in my book. Others are going to be able to help you better than I could but I wanted to give my friendly two ¢¢ on the subject.
You can spray a dilute mixture of Hydrogen Peroxide onto the algae to kill it. Will not harm your plants (unless you spray concentrated H2O2). Algae needs light, so covering that area from the sun will cause the algae to die.