So, you’ve turned off your pool filter and stopped using the chemicals. You’re waiting for the chlorine to completely leach out of the pool walls. You’ll know this has happened when plant life begins to flourish. But that plant life isn’t exactly what you want. It’s a pea soup of algae. (For more about algae check out this site: Smithsonian Institute Botany Projects
The first thing I did after I got the green soup bowl was start to add a couple small fish and a few plants. That process takes a long time to clean up the algae. Since then I’ve found that adding certain plants can clear the water within a couple weeks! In FL, there is an invasive plant called Elodea http://en.wikipedia.org/wiki/Elodea
(the native version of the highly invasive exotic hydrilla) Hydrilla is a plant on our exotic eradication list, so if you do use something like it and you’re unsure, just be sure not to release it into the waterways or sewers. I pull mine out when it gets to be too much and I bake it in the sun for a day and then use it as mulch.
I purchased the elodea at a pet store in the aquarium department. This is why you can never be sure of what you’re getting. Submersed plants will clear up the algae the fastest. The potted plants are important for long term care since they compete for the nutrients. Algae are plants that need sunlight, oxygen and nutrients just like any other plant. So by covering your pond surface space with at least 65% vegetation, algae cannot survive. It will still grow on the sides, but so many things eat it that it hasn’t become an issue for me or any of the other ponds I work with. Photo on the right is elodea in bloom in April. Right after this I pull about half of it out to use as mulch.
One more tip for this soupy stage: hydrogen peroxide. You may have heard that barley straw can eliminate algae. The by-product of barley straw decomposing is hydrogen peroxide. It’s safe for all the good plants and all the critters, although at this stage you probably don’t have many to worry about. In the 22,000 gallon pool I used 16 32 oz. bottles. Get them at discount stores for about $1.50 or less per bottle. It really helps to jump-start the algae killing process. It’s good to have some small filter at this point as the algae dies off and leaves decaying plant material in its stead.
Now here’s my story about filtration. I was so afraid of it going wrong when I started that I purchased an inline bio filter made for ponds. It was way too strong and started to suck all the tadpoles and beneficial insects, dragonfly larva, etc. into the skimmers. So finally I turned it off and disconnected it. Lesson learned. There are lots of wonderful and inexpensive filters that worked just fine to clean out dead algae and other debris. This is one of my favorites. I also tried the UV filters that were recommended to me only to find that they kill the good stuff with the bad and now I reserve them for the day I have a pathogen or other issue. It’s been 8 years and I’ve never had any issues.
These little filters also are convenient since you can move them around. I like to use their fountains for oxygenation of the water, but not around lily pads since they don’t like water movement or too much water on their pads. They breathe through their pads. These have filter pads that are simple to clean and reuse.
Fish and plants will keep the pond balanced. The fish eat mosquito larva as do the dragonfly larva and tadpoles and lots of other neat bugs. The adult dragonflies and frogs eat the adult mosquitoes! The filtration, minor, is to clean out dead algae. I turned the spa into a bio-filter by lining the seats with plants and using a submersed filter just like the one above, only attached to a hose (instead of the fountain piece) that comes up out of the main pond and into the spa, the water goes through the roots and out the waterfall, adding oxygen. I find you can never have too much oxygen. In the summer here (very hot) oxygen escapes faster so in the hot summer days, I turn the fountains off during the day and on all night. In the winter I do the opposite, and this year I only turned on the fountains during warm days for extra heat in this unusually cold winter.
Just toss in some elodea. You’ll be amazed at how fast it grows and takes down the algae. It doesn’t like the cold though, so up here I’d say wait until March 1 just to be safe. You might be warmer. Here's how to test the water quality , use very small, young fish since they adapt faster. The older the goldfish, the more difficult it is for them to adapt. (And I recommend goldfish since they are hardy and cheap) I let my pool go in August, so it got really bad with the high heat. I think I tired two or three small goldfish in September, but they didn’t survive until the spring. It may have had more to do with the lack of oxygen than the chlorine issue since I hadn’t found the elodea solution yet and that many algae leaves little oxygen for the fish.
So those tips should do it! The main thing is to trust nature. It’s amazing how brain-washed I had become by the whole pest control mentality. When I stopped using all chemicals in my yard and home I was sure I’d be overrun with critters! It has never happened. Lizards, frogs, birds, they all eat each other and they ALL eat bugs! I can’t wait to hear of your progress and see your photos!
The Pondmaster Filter at Foster & Smith
Tetra above ground filter at Foster & Smith
I am not endorsing any particular vendor, info only for information purposes.
And special thanks to Janet for the questions that led to this article! Keep 'em coming!