Not in my reactor, I had no idea that people used anything else than water. I just learned a little while ago that they suggest you use FW rather than SW in the bubble counter because of pH or something (I can't quite remember, I just went "oh, hmm" and moved on
). I've used glycerin in various other crafty type things
I just got a new reactor and it will be interesting to see how the water levels in the bubble counter do. My previous reactor went for 3 years without needing any extra water put into the bubble counter. I didn't think it could evaporate.