Question: “There’s some stringy green moss growing from rocks in our pond.  Is that an issue and should we pull it out? – Minnesota pond owner

Answer: Jeff says, ” Thanks for reaching out!  That stringy green moss is a plant- filamentous algae to be specific. Some string algae is not bad but the amount in your pond is close to undesirable. (I.e. large mats of stringy green stuff). Like other types of algae, the stringy kind is simply enjoying nutrient-rich warm summer pond water.

You are welcome to hand pull it out but I would suggest adding some water treatments to your pond to consume the nutrition in the water so the algae does not come right back!

String Algae is a plant, similar to “weeds” like dandelions on land.  Plants need light, water, and nutrition.  Adding water treatments like beneficial bacteria and desirable plants like pickerel rush or water lilies will help “starve” the algae.

Get some plants you can enjoy the beauty of (shameless plug for our greenhouse! www.mnponds.com/plants). Also, add beneficial bacteria once a week.

If you want a more intense approach, add SAB every morning until the algae disappears.  Keep adding bacteria once a week also.  The SAB breaks down the algae in your pond and the bacteria digest the nutrients.

Other intense control methods for pond algae include using an Algacide like Aquascape’s Liquid Algaecide or powder algaecide called Ecoblast which can be sprinkled directly on the string algae.

Copper can control algae and using an IONGEN probe will use copper to mask the problem but require constant monitoring and possible water algering. (We’ve seen copper and copper probes cause other issues down the road.)

If the algae continue after this hot spell, you may want to check if your pond has a leak.

 For leak testing or repairs, feel free to give us a call or DIY the process by following these pond leak steps here.

Happy Water Gardening!

Jeff