You put 2oz of Clorox in 15 gallons of water Will that harm a 90lb dog?

According to the EPA website, drinking water can be sterilized with 2 drops of household bleach (Clorox) per liter. That's 7 drops per gallon, and in your particular case that's 105 drops for the 15 gallons. 2 ozs is a lot more than 105 drops, I'm pretty sure so let's go at this a different way. The above recommendation is using a ratio of 1:4000 (Clorox to water). 1 gallon has 128 ounces -- 15 gallons has almost 2000 ounces. So 2 ounces would be a ratio of 1:1000 -- that's 4 times too strong based on these guidelines. For 15 gallons a safer amount would be 1/2 ounce of Clorox.

But will 2 ozs harm the dog? I don't know what the upper bounds are...doesn't matter how big the dog is -- it's the ratio of Clorox to water. Clorox will evaporate more quickly so maybe the concentration doesn't stay that high if you don't retreat it often.