Algae do not harm plants, but they can slow gas exchanges into and out of the growing medium, which can slow root growth.

Is algae bad for plants?

Algae can build up on your soil due to excess moisture and humidity levels but there's no need to worry! While algae do have their own photosynthesis process, they're not harmful to your plant and can be removed quite simply.

Is it OK to water plants with algae water?

If you're watering your vegetable garden, various microbes can cause an array of illnesses. You could get severely sick if you don't treat the algae-filled water before using it on your plants. Furthermore, it can be bad for the plants, drying them out and infecting them quickly.