I’ve had lots of calls and emails regarding pond algae in the last few weeks. I wrote an email newsletter to address the most essential issues of this problem.
Recent events related to our water garden prompted the following:
Our spring lasted all of two days this year and was followed by a very unseasonable spike in temperature – upper 80’s is very rare for May and early June. The rapid weather change brought quite an algae bloom to our pond, and, to be honest, I was unprepared to respond promptly. The discussion about algae below will allow you to deal with this issue effectively.
Types of Algae
The two main classifications of algae in ornamental ponds are string algae (aka blanketweed) and suspended algae. The former type is bright green, sometimes attaches itself to rocks and often floats around the surface of the pond. String algae can choke the growth of aquatic plants and operation of skimmer and pump if not controlled. This is the type of algae that recently got ahead of me here.
Suspended algae are tiny single-cell organisms that turn your pond an ugly pea soup green.
Control of these two algae types is quite different; for string algae, preventative measures like liquid barley straw extract can be helpful, especially if started early in the season and continued regularly. Serious blooms of string algae must be stopped with a product like AlgaeFix, used carefully according to directions.
If suspended algae becomes a persistent problem, the only real solution is to install an ultraviolet sterilizer. The ultraviolet light actually kills the algae organisms, as well as any harmful bacteria that could make your fish sick. Years ago we installed an AquaUV 40 watt clarifier here and have been very happy with the excellent quality and performance. We now carry the complete line of these units, for very small to very large ponds. See this page for more information. And feel free to call us toll-free for more information on these units: 866-816-4769.
Like most garden and landscape issues, the total ecology of the water feature will affect each of its parts. If the water is kept clear and healthy, other issues will be more manageable. Products that continually add beneficial bacteria throughout the season are excellent for general water quality; see the Healthy Ponds Value Pack and the Aquaspheres at this page.