I discovered some kind of worm that is eating the leaves of H. polysperma in my 
tank.  I removed four of them that appeared to making a nest by sticking the 
leaves together in a manner very similar to that I have seen with caterpillars 
in trees.  They even look like caterpillars and are roughly 1 inch in length.  
I suspect that if I found four that there are many more still in the tank.

Is this is common problem, and is there a fish that could easily remove them?  
Currently my tank is only stocked with Otto's and some small SAE's.

Don Hutton