If you just start over with the pool, you are in effect still doing the tub tests but just in a very big tub! So, you aren't saving anything there. However, as you noted, if your daughter has a reaction, then you will have absolutely no idea which ingredient caused it and will never know, and you're right, you would be done with the pool. Not only would you be done with your pool, but your daughter would probably be done with pools, period. How would you ever be able to allow your daughter to swim in any pool ever? What a shame that would be for your daughter to never be able to go swimming.

Good luck. Please keep us posted how things are going. (Also, please let us know if you are going to do the tub tests before Ben goes to the trouble to figure out all those doses for you.)