Do any of you have suggestions about my much-more-than-normal crop of string algae? Because of my travel schedule, the heater made it into the pond, but the pump ran all winter. The result is a quantity of string algae beyond anything I've ever seen, and it takes a lot of space in our small pond. It's on every surface, and is thickest, of course, under and near the waterfall. Fish, snails, poliwogs and ducks all go after it, but they haven't made much of a dent. The water is clear otherwise. The pond has a biofilter with several layers of white pads as the filter medium. Is there anything other than manual removal that works?
String algae
String algae is unsightly but it is not bad for your pond. It is merely the algae's response to all the nutrition that is available in the pond in early spring. This nutrition is the waste from the fish and plants from winter and it takes a while for the beneficial bacteria to get started again in the spring (research shows the bacteria is mainly dormant in winter). You can remove a lot of the algae with a round toilet brush (new one for this purpose) used as a wand to twist the algae around the brush. When you bring it out of the pond just untwist. There are products that can remove the stuff without the manual labor but they may upset the natural balance of that beneficial bacteria in your pond which will be coming in about a month to six weeks after the spring algae bloom hits. Hope this answers some of your questions.
Thank you for the advice. Love the toilet brush idea! The water temperature is still under 60 degrees, so the beneficial bacteria probably aren't too active. I have cleaned out some of the areas where the string algae was thickest, and the water remains clear as before. I haven't used any chemicals in the three years we've had the pond, and don't want to start. Green fringe is OK, but this was more like a mane!
I've got a question. Our ponds are only about 130 gallons each and we have been emptying and cleaning the string algae off and refilling them with fresh water every spring. There are a lot of trees around here and some leaves get into the water even with screening over the ponds in the fall, and the dogwood petals and maple seeds and wild cherry blooms get in them in the spring and summer. We put pond heaters in them in the winter to assure that they don't freeze and thus kill the plants. The string algae is dense in the spring before we clean the ponds. My question is: do we need to completely empty and clean the ponds and refill them as we have been doing? Or could we, even with 130 gallon ponds, use the toilet brush to twist the string algae out and a pond vac to get the debris off the bottom and not drain and refill the ponds? The fish, frogs and plants always survive the complete spring cleaning, but it takes soooooo long to do and it would be nice not to have to go thru all of it every spring.
Lotusblossum, Your pond is not able to get to a proper balance of beneficial bacteria with your yearly cleaning. I would remove some of the algae, and vacuum off the bottom of the pond removing up to one third of the water every couple of months for maintainence and fish health. Even half of the water removed would not be too much for the fish. Plus add at least a 2% solution (and up to a 3% solution)of non-iodized rock salt every spring. This salt can be bought in 50 pound bags as an additive for water softeners. Just make sure it is pure rock salt and not one with chemicals. This spring tonic of salt is very good for the fish health as well as for the control of algae.
Ponditis, How do you do the math to figure out the 2%? Our pond is about 1200 gal.Thanks, MW
MW, No way can I do the math :). The rule of thumb is a pound of non-iodized salt per 100 gallons, I add about a cup per 100 gallons with no harm to plants what-so-ever. You can use any kind of salt, even table salt as long as it's non iodized.
mwhit, that would be 24 pounds of salt for a 2% solution.