Tom - I am not an expert on Cutrine. However, Curtine Plus both liquid and granular are algaecides. Chara is also an alga but a little more 'tolerant' to Cutrine applications than the filamentous algae types. The copper in cutrine will slightly supress the rooted plants but will NOT kill them. An early moderate dose of Curtrine may knock-down the fila. algae and stunt early season Chara growth before the rooted plants begin rapid growth. This technique can removing the early season, supressive algae problem. Cutrine is probably the more friendly algaecide compared to more popular types.

Do you have large-leaf pondweed or long-leaf pond weed (they are different)?. Where did you get it? In additon to the plants you now have, I would add some eel grass (wild celery) this year. You can get plants from Wildlife Nurseries, Oshkosh WI. You can also get them in the wild from local lakes. Eel grass will do a better job crowding out the Chara than the pond weed will.
1. What is the maximum and minimum water clarity during the ice free season?
2. Is your clarity stable or is it variable during the year since you pond is spring fed?
3. Do you feed your fish?
4. When does the filamentous algae become abundant?

Remind me this mid-spring to send you a jar for a sample to identify which algae you have when the growth gets blooming. A spring fed pond can develop cool water forms later & longer in the season than a typical pond. I'm guessing Oedogonium or Mougeotia.

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