Well, after much research and gnashing of teeth, I’ve finally settled on a solution that looks like it will bring our pond back from the brink of eutrophication. It took a fair amount of research, a bit of sweat, and not insignificant amounts of money, but it didn’t break the bank, either. I think I went about it backwards, or at least sideways, buy hey, it’s the results that count, right?
After a couple of false starts with algaecides last year, I realized that those chemicals were just contributing to the problem. Kill the weeds and algae with chemicals, making them die and cloud up the water, depleting the oxygen and causing another cycle of nasty plan growth that further reduces the fish population.
So I went looking for a more ecologically friendly and more effective approach. I found what I was looking for through a company called Airmax. They have a four step process, and being a cheapskate and contrarian, I started with Step 2, a bacterial agent called Pond Clear that is designed to “eat” the nutrients that noxious weeds thrive on and clear up the water. This stuff had an immediate effect, and after cheaping out on a couple of gallons of the liquid, I bought a bucket of packets that should last a full season for my ¼ acre pond. After only a few months of treatments, I’m seeing schools of tiny fish that I don’t think could have survived before. They also offer blue pond dye and something called Nutri-Defense, and “eco-enhancer” as steps 3 and 4. I’ve used the dye a couple of times, but haven’t yet tried step 4. But from the results of Pond Clear, I’ve definitely drunk the, um, pond water.
Well, back to step 1: aeration. I sort of choked at the $1,300-$1,500 price tag for the fancy high high-end aeration systems, and I also wanted to look into solar aeration, so I did a lot of looking. For what I found, I’m not convinced that there is a viable solar system our there at a cost that justifies the cost of electricity. If you can’t get electric out to the pond, that’s another matter, but what I found it that most solar aeration systems are very expensive, underpowered, or cut out some elements (such as a battery) in order to be more affordable. And of course, they need sun to work, so even without the price differential, an equivalent system is going to deliver less constant results.
I opted for an electrical system. The primary criterion for sizing a system seems to be the Cubic Feet Per Minute (CFM) of air it delivers. I’m not an expert on these things, but it seems to me that all of the fancy check valves and aluminum casings and cooling fans just suck more energy and run up the cost. I opted for a system through a website called fishpondaerator.com. I got the medium pond system which delivers 8/10 CFM, and it cost less than $300, by far the best price I saw anywhere. It was a bare-bones system with just a small diffuser, some hose, and a pump. I built a pump housing out of a plastic milk case, some plastic foam insulation for soundproofing, some PVC pipe to bury the hose between the pump and the pond and $60 worth of direct burial electrical wire.
The diffuser is a weighted bottom tube, because the oxygen has to get to the bottom to get thermal turnover and to oxygenate the lower parts of the pond. I’m expecting the fish to start jumping up onto shore any minute now, so I have laid out some frying pans at strategic locations around the pond.