Minnesota is a midwestern U.S. state bordering Canada and Lake...

Minnesota is a midwestern U.S. state bordering Canada and Lake Superior, the largest of the Great Lakes. The state contains more than 10,000 other lakes, including Lake Itasca, the Mississippi River’s primary source.

MPRNews.
“As algae blooms spread, more Minn. lakes get chemical treatment
Daniel Ackerman · Plymouth · Jul 5, 2019
….But Bass Lake is threatened by an explosion of tiny floating plants called algae. These algae feast on phosphorus, a nutrient that bubbles up from the lakebed sediment and causes the algae to reproduce like crazy. Algae blooms can turn the whole lake green….

And Bass Lake is not alone in its water woes. Harmful algae blooms are growing more common across the state, according to research from the University of Minnesota.

To combat the aquatic scourge, lake managers are increasingly turning to aluminum sulfate, or "alum" for short. The chemical blankets the sediment, keeping the lake's phosphorus levels in check. And without phosphorus, the algae starve. That can turn the lake from grimy green to crystal clear.

That's why lake scientist John Holz came to Bass Lake. After 16 years researching lake chemistry, Holz founded HAB Aquatic Solutions. The company has injected alum into more than 80 lakes since 2013, including 16 in Minnesota. Holz's crew applies the chemical to Bass Lake from their high-tech tanker barge…

While the alum smothers phosphorus in the lake bed, it cannot stop phosphorus carried into lakes by streams. So Holz emphasized that alum treatments work best only after lake managers have reduced phosphorus in a lake's in-flowing streams.

Holz added that the process is benign. "As long as it's applied safely, there are really no negative components to an alum application," said Holz.

Most outside experts agreed that harmful side effects are rare. However, if the lake turns too acidic during an alum treatment, it could kill fish. Holz is monitoring the acidity throughout the day, so the lake should stay safe — not just for fish but also for human swimmers. In fact, Holz uses the same food-grade alum that water treatment plants use to purify drinking water…”

Frustrating though this might be for me, several issues are highlighted in this article that indicate Phoslock’s treatment superiority and potential.

One is “that alum treatments work best only after lake managers have reduced phosphorus in a lake's in-flowing streams.” No method has ever been developed to address this. Unlike Phoslock.

Two is “ Most outside experts agreed that harmful side effects are rare. However, if the lake turns too acidic during an alum treatment, it could kill fish.” There is much evidence, including but not only fish kills that suggest the experts are wrong (or bought).

Three is the pure scale of the algae/water problem in one US State. 10,000lakes.
Four is that alum treatment is quite common in the US and that phoslock can rival and relplace it.