Then I suspect it will be OK in a year or so
as long as you have no concrete (or certain rocks, as these exacerbated the problem in my pond). pH certainly plays a role too; if I remember, an acidic pond is better. The strands tend to break up at lower pH.
Can you post a picture of the problem just in case it's not blanketweed (you call it "blanketweed-type stuff") or anything else can be deduced?