JCD,

When you drained your pond, you lost all the minerals that make the water "hard". (the harder the water the less fine clay it can hold in suspension)

If most of your new water is soft, acidic rainwater, you'll have to wait for minerals to leach out of the soil and harden the water. That could take a long time, depending on the soil.

If you can borrow someone's well water, that's about the quickest way to harden it up. If not, add ~400# of gypsum at a time, and watch for clearing. At the 1st sign of clearing, stop, because it will continue to clear over time. If it takes more than about 1000# of gypsum, you can add a few bags of alum, as it's stronger. Using hydrated lime can cheapen and accelerate the operation. It's more base (higher PH) than gypsum, and much cheaper.

Alum dissolves almost instantly, so just dump it on a bare spot with waves and watch it disappear in an hour. Gypsum dissolves a little more slowly, but will still disappear in a day or 2. Hydrated lime dissolves much more slowly, so spread it. It will sink to the bottom in a thin layer, and dissolve over a year or so depending on the water's PH. Hydrated lime can be a little rough on your hands, and stress fish. If you decide to use it, it's a good idea to spread it in a barren spot.

I buy alum and gypsum in 50# bags from a local nursery . I get 50# bags of hydrated lime from a feed store, where it's cheaper than the nursery.

Shrimp