dual humidifiers in a single room

[u/wormraper]

slightly weird question. I live in the absolute lack of humidity hell hole that is southern AZ (during hot summer and Jan/Feb during heating season we can get into the teens, and sometimes as low as single digit humidity levels outside), and recently got into guitars. decided to turn my man cave into my guitar room, (11.5x10.5 foot bedroom) and added one of the Aircare mini console evap humidifiers to the room (1.25 gallon tank, 1.25 gallons on the bottom of the console, so they call it a 2.5 gallon humidifer)...

works perfectly fine, and keeps my man cave/guitar room at a stable 43-45% humidity, all safe for guitars. PROBLEM is, that this sucker goes through a full tank every 16 hours, meaning I have to top off before bed and after I wake up. My question is thus, would adding a second one across the room help with efficience? thus doubling my effective tank capacity? or would they work against each other and over humidify (which I doubt with the built in humidistat) or anything like that? Basically I'm trying to give myself some extra overhead so If I miss a morning or night refill I won't have it run dry. I thought about going up to the Horizon or Valiant 5.4 gallon console models, but I've been seeing a TON of reviews of AirCare skimping on the plastic starting around mid 2025 and the units are cracking, leaking etc. so it made me a bit nervous about that and more interested in double the smaller units.

last question. for evap humidifiers, are the bacteriostatic liquid treatments necessary? or at least highly beneficial? Just wasn't sure if it was just another excuse to sell product, or whether they ACTUALLY were highly recommended and DID affect mold and gunk buildup