Trying to get rid of a hydrilla problem in stock tank. I've heard grass carp, tilapia, chemicals...
Anyone have a good suggestion or preferred method?
There are folks about, surely some near you, that get paid to take care of such problems and give advice. You might get five ways from five of them, but....
In August in Texas ALL of them will agree that chemically treating hydrilla in a lake or pond is risky business.
Besides, who identified the "weed" as hydrilla? There are many submerged and emergent aquatic plants, only one of them is hydrilla.
My preferred method is,
1) Identify and quantify the problem
2) investigate and research possible solutions and identify those that are consistent with goals for the pond
3) implement the chosen solution
Now you might get some good advice 'round here, but it would help a lot if you posted a picture of this hydrilla and maybe even of the infestation in the pond plus a lot more info like size of pond, fish in it, etc.
Almost always when dealing with such issues I find the pond owner never gave any consideration to shoreline plants, emergent aquatic plants for landscaping, erosion control and habitat formation, type and condition of watershed (or water supply like a well), water chemistry (hardness, alkalinity, pH etc.), or even outlining any goals for the pond.
Might almost be worth giving one of them folks what gets paid to help out with such things to make sure you are doing the right thing....