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Armour finds algae-fighting success with SolarBees, carp

This SolarBee in Armour’s Lake Alcazar is one of two solar-powered recirculating pumps that have been credited with improving water quality in the lake. (Ross Dolan/The Daily Republic)

ARMOUR — Clear water. That’s been the result of using solar-powered recirculating pumps and a plant-eating species of carp to reduce water weeds and algae in Lake Alcazar, a small body of water in Armour.

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The water is so clear the American Pointing Labrador Association will use the lake for its South Dakota Fall Hunt Test next weekend.

Scott Olson, of Corsica, who is helping with the event, said the specter of smelly, algae-covered canines kept dog enthusiasts from using the lake in the past, but water clarity improved vastly in recent years.

“Today the condition of the water is much better than we would require,” Olson said. “These guys have put a lot of work into this lake and they deserve a lot of credit for its improvement.”

Armour City Superintendent Dave Majerus agrees that plant growth isn’t as thick this summer at the lakes. The SolarBee recirculating systems have also kept the lake open in the winter over the past two years, since the units remain in the lake year-round. He credits the machines with vastly reducing fish kills that typically occurred each spring before the SolarBees were introduced.

The two SolarBees — one each for the east and west sections of Lake Alcazar — are floating, solarpowered recirculating pumps that help to oxygenate the water and reduce organic sediment. The pumps use deep water intakes to draw lower water to upper levels.

The pumps were originally purchased for use at the city’s sewage lagoons, but they were replaced with a more effective aerating pump about two years ago, Majerus said. The SolarBees did well enough handling their sewage chores, but they were originally designed to be used in lakes. The city decided to clean up and sanitize the units and see if they could help improve Lake Alcazar.

The football-shaped lake, which is nearly divided in two by a median peninsula, was plagued with weed-choked shores and the water was filled with heavy blooms of algae and milfoil, a water plant, Majerus said.

Armour city workers also introduced about 35 Asian grass carp to help with lake cleanup.

“The grass carp eat down the vegetation,” Majerus said.

Before the carp were introduced, water milfoil clogged the lake and, in turn, helped to support algae growth. Overpopulation of the carp won’t be a problem because only specially produced sterile fish are used in the lake, he said.

What the fish lack in numbers, they more than compensate for in appetite. In larger bodies of water, the voracious carp have been known to grow to more than 100 pounds in size and to eat three times their body weight daily in plant material, Majerus said.

“We’ve been told they probably won’t get larger than 65 pounds in our smaller lake,” he said.

The Lake Alcazar SolarBees are similar to a SolarBee unit that has been used at Lake Mitchell in recent years.

The jury is still out on whether the Mitchell unit has helped to reduce algae blooms in its portion of that considerably larger body of water. A battery failure also meant that Mitchell’s SolarBee wasn’t operational during one summer season. One reason given for the lapse was that city workers said it wasn’t easy to tell if Mitchell’s unit was working.

That’s not a problem in smaller Lake Alcazar, Majerus said.

On still mornings, he said, water in the two sections of the lake can be still — until the sun comes up and the solar-powered pumps kick in.

“You can tell when they’re working,” Majerus said. “You can see a little wave move across the lake.”