Product review (1 stars): Horrible
I have heard a lot of great things about the hydra lg.  I already had a hydra sm in a 300 ct humidor and had no problems.  The lg has been nothing but trouble though.  I got it a month ago, for a 3,000 ct 16 cubit ft tower humidor, and it has not kept the humidity at all.  The built in hygrometer is obviously wrong. It reads 75% rh when it is only 55% rh.  I can't recalibrate it because the calibration knob is already turned all the way.  So I can only make it read higher.  Then today I checked the basin and it had mold in it.  It really smelled.  I have thousands of dollars worth of cigars and that could have been devastating.  I contacted the manufacturer and they are sending me a new one.  I don't know what I'm going to do in the mean time though.  I can't not have a humidifier for a week.  I am switching to humidity beads.  They are very accurate and no mold.  I hear you can even put them in the hydra in place of the foam. I might give this a try.  In hind sight I wish I either paid more for a really nice electric humidifier like avello or just used beads in the first place.