Yes, I have been mulling this over all day. It seems like It needs 4 gallons a day to keep the chlorine up at 3 or so.
Wayne, you're missing something basic. How does your water look? If it looks great to you, you don't have to add back to 25ppm each evening.
from an earlier post:
If your water is not yet as sparkling as you'd like, Test and add enough to get you back up to the 25ppm range.

Once your water is fine, test and then add enough Cl to stay within an 8-5 range. You'll probably add quite a bit for the first couple of days, then your Cl consumption will drop off as you no longer have to kill so many "bugs"
Post back with questions....your last post indicates you do not have an understanding of the shock process you're going through.