Anyone out there in nexus land know what CLR or calcium lime rust remover, is, and whether or not you think it will kill mycelium?

lol, no idk what that it, but it sure doesn't sound healthy for the mycelium. its "rust remover" man, which means it prolly has other chemicals in it to remove the oxidation from iron
what do u intend on using it on the myc for? if its to increase the pH of the sub to counteract the myc acidity, then there are better, and safer alternatives imo

CLR is fantastic for cleaning glasses and crystal with a 'film' or buildup of calcium. Just run some hot water in the sink with a cup or so of CLR and let your dishes soak for an hour or so - they will be like new. Also works great on cleaning the shower and sink and many other things.

It should kill mycelium just fine, but as Phantastica stated, there are better alternatives.

Thanks guys.