It's only gross if the taste of your hits are gross, or if you start to see life forming in the water. I changed my dab rigs water maybe twice a year, and it's never gross, unless you think floating reclaim is gross. Twice a year I'll clean the rig with iso, but I'll save it all in a glass and let the iso evaporate and I'll be left with some reclaim that a buddy of mine loves to use for making his own edibles. Win win for me. Lol.

My dab rig has had the same water in it since trump was president, except a little bit has evaporated. I rarely ever use it anymore but if I did, I'd just add some more water. It definitely isnt time for a cleaning.