Oh... I have the pump from our pool cover... would that work if I put it on the top step, and then the next step, etc?
Make sure your pH is inline as well. And Texas is of course right about the pool store!It's generally safe to swim as long as you can see the bottom and your FC has not exceeded your corresponding SLAM FC based on your CYA. Since your CYA is exceptionally high at the moment, I don't see a problem in that.
If my 8am math is correct, the target for CYA 220 is about 24, which is 5 gallons.
If I were in your shoes, I would get a submersible pump and get the water replacement over sooner than later. It's seems wasteful to get your water in order then just dump 75% of it.