ProtecArion In-Case Humidifier

Holds a huge amount of water so only needs refilling every couple of months. Gradually releases humidity in the case; probably would not do the trick to dehumidify a dry instrument but to maintain a steady 40-45% it is perfect. Note: use distilled water, and I put an elastic over the lid just for a little extra bit of assurance that it cannot come off. Also note it is quite large so probably would not fit in small or tightly-contoured cases.

The negative reviews puzzle me: apart from it being somewhat large, and possibly not fitting well in your case, it works perfectly.Keep in mind that the best equipment of any sort is going to perform poorly if not used correctly.I use them for all my steel (6 and 12) string acoustic and my nylon string classical guitars.This humidifier is meant to be in the case (with the guitar also in the case), not inside the guitar.Placing it up by the head is not ideal, as the wood that needs the humidity is the body of the guitar.If you move the case around a lot, you may want to put the unit inside a soft cloth pouch, to keep it from rubbing the guitar.Putting it inside the accessory compartment will work, but is also not ideal.I keep mine snugged in the gap between the guitar body next to the heel of of the neck, and the compartment section.It will not humidify your guitar outside of a case; it is not a room humidifier.This even works adequately in soft-sided gig bags... as long as it is with the guitar in a small enclosed space it should work well.It works for well over a month between refills, and keeps the case in the 40%-45% humidity range, which is ideal (and I'm in dry Colorado, too).The time between refills depends on how tight your case is - in my experience, it's good for several months inside a hardshell plastic case with good edge seals; with a nylon/foam gig bag it's good for about a month.The more sealed the case, the more consistent the case humidity (less variable with the weather).It has a clearly visible water fill line - fill it up to that line, and no further, with *distilled* (important!) water, and you will have no troubles with water leaks, excessive dampness, or with the product's longevity.Even when the hydro-gel crystals are shrunk/dehydrated to about 1/3 of the "full" volume, it is keeping the humidity up in the 40% range.That's about when I refill it.Let the freshly refilled container sit upright for about 5-10 minutes to allow the crystals to absorb all the free water before putting back in the case.On first use, your case is probably very dry, and it will take some hours for the case to reach equilibrium, but once that happens this humidifier keeps the case in a steady, reliable humidity level.

I have used Arion case humidifiers for years. Most humidification systems require relatively frequent refills, and tend to operate unevenly -- a bit too much moisture when first filled, rapidly declining moisture levels starting almost immediately. The Arion contains the kind of moisture retaining hydrogels typically found in cigar humidifiers in an oblong, clear plastic container which is just permeable enough to allow water molecules to escape with no leakage. The system releases moisture slowly and steadily and requires no attention for weeks. You can easily see through the transparent case when refilling is needed. Unlike some systems, regular tap water, not distilled water, is all that is required. Over time I have had three of them; my impression is they continue to work almost forever, but they become somewhat less effective after several years

Very good product. It does not leak - if you follow the instructions ;-) I love that you do not have to check it every few days - it last for weeks between fills, so it is perfect for a guitar that has to sit idle in my closet for some times.

SLOW: Speed is related to the size and starting humidity of both the instrument and the case. It may take a while on first use. Gradual changes are better anyway.FILLING: Follow the instructions! Fill to the line, then wait for the water to be absorbed before putting it in the case. Once absorbed, there will be no leaks because...LEAKS: Properly used, there's no liquid to leak. The water is captured in the gel and slowly escapes as vapor. Any water leak is from damage or not following instructions.REFILLING: Totally depends on conditions and usage. Close the case when the instrument is out.CAP: Use an elastic band to keep the gel from spilling if the case is knocked about. Or a thin soft pouch.GUITARS: Yep, they're big for guitar cases. The size is part of how they last so long. They fit in the heel area of all my cases except a 3/4 where it fits at the head. Close to the body is best, of course.CELLO & DOUBLE BASS: Need several. More instrument and more case to humidify.