Even without any bleach or salt, the perlite takes a looong time to contaminate. Even in the summer I’ve neglected to clean the chamber for months and didn’t notice any foul smell or obvious signs of contamination. Adding a pinch of something is a wise precaution though IMO, there’s nothing to lose aside from potentially weakening the plastic, airstones, tubing etc.
What i do, is i use a mixture of 40% hydrogen peroxide and 60% distilled water for the water I have under the perlite with my bubble-stones running in them. I think it works really well, and even if it ever happens to splash into my substrate, its not like the hydrogen peroxide will hurt my mycelium. And from then on, about every 3 days, i take out my trays, and squirt more hydrogen peroxide in there on the top of the perlite and on the walls and ceiling, to make up for any drying out, and to make sure everything stays good and semi sanitized... adding a little salt to the water may be a good idea as well, i just use hydrogen peroxide for EVERYTHING, and i think i have a pretty decent sterile tech.. Just my 2 cents..
Edited by ChocolateStarfish, 01 June 2020 - 11:23 AM.