Water changing in hot climate.

[Texgal57]

We live in southern GA and give our chickens water with a gamma lid covered 5-gallon bucket with nipples. We have the bucket in our tarp covered run which is in the shaded part of our yard. However, with the humidity the temperature feels like upper 90's to low 100's many days (out of the shaded area, but still gets warm in the run). We're trying to figure out is we should just keep topping the water off daily, or if the plastic will leech into the water due to the heat and humidity, leading to it needing to be changed at times. I've read people say you just top the water off, but I didn't see anybody from southern states comment. Would it be the same, or should we change the water out?

I live in Central Texas, I just add ice to my waterers and top of as needed. Adding shade cloth to block out any sun will help with both algae and water temps.