You're more than welcome. You can find the algae fix at Petsmart, or if you have a Petco near you, they should have it. I'm sure ADI doesn't sell it. The Algae Fix will take care of all that algae. Waterfall and all. As long as the water comes into contact with it, the algae is done.
That's great that they made it so deep. Remember that the deeper a pond is, the more stable that pond's temperatures will generally be. When in doubt, go deep!
I'm definitely looking forward to seeing pics. I want to see what we're dealing with here.
You answered all of my questions. All I need to do now, is see the pics tomorrow.
Have a great night!