Cecil --
I have had some luck with copper -- but not as much as I would like. It seems to work best early in the year. Later applications haven't been very effective at all. I use it as sparingly as possible now, mostly because I used way too much the first season I owned this pond (2002) and before I put trout in.
And I have to wonder sometime if chara doesn't build up a certain tolerance for the stuff.
Larry --
I've considered getting more grass carp. But from what I've read, they're effective with chara while they are less than 20" in total length. Apparently, at that size, they start to switch over to more substantial plants. I can get a permit from Virginia Game & Inland Fisheries to get up to four triploid grass carp for a pond my size (the original pond owner put in eight about 12 or 13 years ago).
A local supplier deals in 8" triploid grass carp -- I'm pretty sure they would grow to 20"+ in their first season; thus I would probably be purchasing them every year ... and that could get a little expensive. And I have to tell you, once they're in a pond, they are probably going to be in there for a long, long time. Very tough fish to remove, in my experience.
The cage I plan will be just about 30 cubic feet, 5' x 3' x 2'. I want to start off with about 25 6"-8" brook trout (just about the size my few remaining channel cats enjoyed as "snack food" last November). If I can get them in by November 15, I would hope to harvest 10" to 12" fish by March 30 or so. A local fellow starting up a restaurant has indicated an interest in purchasing some. He's a first-time restaurateur and I'm a first time fish-farmer -- ought to be interesting!
I'd really love to try cage culture of either blue or Mozambique tilapia -- but Virginia bans "open system" i.e. farm pond, culture of tilapia; they allow indoor closed systems only. I think the sudden appearance of northern snakeheads up in the Potomac drainage a few years back has made the Commonwealth especially cautious with any potential non-native critter that might conceivably establish itself in Virginia waters. -- Mike
