When earthmoving equipment is on the property to do grading and foundations for the house, that is the best time to do a pond renovation project!

I would suggest you keep doing research on Pond Boss forum to determine your best course of action on your pond. There is literally an expert for almost any question that you can ask.

(My problem was that you need to have some knowledge about ponds to be able to ask the experts the "right" questions.)

Good luck on your house and pond project!

P.S. If your pond dimensions are actually a 150' x 150' square, then your pond is 0.52 acres.

Best wishes, Rod