Floating Pond Scum And Surface Growth

A common problem in many ponds is a form of floating growth that is quite often a form of algae or a pond weed.

For Algae Problems

If the plant has a spinach like appearance it's usually a form of filamentous algae. In general, like most unwanted plant growth that derives most of it support from nutrients in the water we suggest using a natural bacteria product which can help lower nutrient loads in the pond (which algae feeds on) and you can find the right beneficial bacteria here.

surface algae Choose the correct product based on your pond's gallon volume. Note as well that if you know you have a heavy organic load in the pond (such as many leaves or heavy fish loads) then you'll want to increase the dosage up to 2X the pond's volume.

Be advised that whenever you use a biological or bacteria based product, they often work best with adequate aeration or oxygenation of the water. If your pond is fairly stagnant it's usually best to add aeration first, before attempting to treat with bacteria. Learn more about pond aeration systems.

If the growth is around the edges of the pond, we often use a product called Algae-Off which is a contact algaecide that can be used for spot algae control to knock down unwanted growth. We normally don't like to use this product for pond wide cleaning but it works very well for spot treatments and for small ponds, it works well around waterfalls, rocks, stream beds, and other hard to treat areas. Learn more about Algae-Off here.

If your pond is fairly shallow (less than 6 feet) it may be helpful to limit sun exposure and light penetration into the water. Aquatic dye can be helpful for this and we carry 16 oz bottles for small ponds and one quart bottles for large ponds.

For many ponds it may be desirable (although not always easy) to remove the algae manually. To make the job a bit easier a weed or algae rake may be helpful. The Algae Witch is best suited for small ponds. Visit this link for pond weed rakes.

For Pond Weeds

The most common floating weeds that you'll find in larger ponds is a form of duckweed or watermeal. In smaller backyard ponds duckweed is often desirable, but in larger ponds it may not be.

Biological tools may be helpful if you begin using them before the duckweed appears. Once it show's up it's important to treat it early and not wait very long. Once the plant is well underway we usually suggest letting it run it's course through the summer. It's much easier and cost effective to treat early.

For duckweed and watermeal specifically, look for products called Sonar or Weedtrine-D.

If your specific question or problem has not been covered here, please contact us for additional help.

If you have questions that you'd like to ask here concerning pond weeds and surface growth please use the comments section below and we'll share our discussion with other pond owners.