What makes the MN300 better than other sponge guitar case humidifiers is its special sponge and intuitive design.

The "Humid-i-Bar" sponge absorbs more water than other sponges that I've tried. This ability to hold more water allows it to work consistently longer, reducing the need for water refills.

I'm also impressed with its anti-drip design, even when fully soaked, water doesn't leak. Only a few drops of surface water drips back down to the bowl. This makes me confident that the sponge really is safe for guitar use.

The sponge goes inside a case that's very easy to use, and comes complete with an easy to open top cap with basic instructions. It is designed specifically for soundhole mounting. It is thin enough to slip in-between strings, and thick enough to be held up by string tension.

The top portion has flaps that allow the unit to rest on the strings. Being a sound hole humidifier allows it to more efficiently maintain the humidity of acoustic guitars, and this is exactly what I use a guitar humidifier for.

Like other sound hole humidifiers, it does apply a bit of stress to the strings, bending them sideways out of their regular position. But in my experience, it's not bad enough to cause any substantial problems - see my video below to see for yourself.

Since the sponge doesn't leak, you can actually place the Humitar inside the guitar case, just make sure that it is placed where it won't accidentally scratch or damage the guitar. You can place it in the space below the headstock, or inside internal pockets - as long as the case is stationary.

Humitar MN300 Packaging.

Easy maintenance is another big reason why I give the Humitar my thumbs up. All I have to do is open the top cap, and press on the sponge to feel if it's soft or hard. If it's soft, it still is working fine, if is getting harder, then I can quickly pull out the sponge and soak it in distilled water.

Taking out the sponge quickly also allows me to check for discoloration that could be symptoms of problems like mold, dirt and debris. The sponge's light color makes it easier to see problem spots. Maintenance is easy and fool proof.

All in all, I'm very pleased with the MN300, highly recommended for guitarists that want an efficient and easy to use humidifier.

Specifications

• Weight: 2.9 oz
• Suspension: Held By Strings
• Longevity: Medium

Demo

Here's a short video I made showing you the steps to set it up for the first time.

Instead of using a sponge, the Oasis OH-1 uses a special type of gel to humidify without leaking water on your instrument. This allows it to work just as well as sponge types, while having a smaller profile that's easy to position and maintain.

The OH-1 looks and operates much like a syringe, with a stabilizer bar that allows it to sit on top of your instruments' strings. Once it's properly setup, it is designed to maintain 45% to 55% relative humidity inside the guitar body, when outside humidity is within 25% to 40%.

Maintenance work is quite simple, you just need to open the top cap and pour in just enough distilled water. The water is then absorbed by the Humigel crystals inside, these crystals are super water absorbent, and they serve as the humidifier's sponge.

The exterior is made from a special cloth that prevents excess water from leaking out while allowing evaporated moisture to pass through.

Needs refilling - Image Courtesy of Oasis.

The Humigel crystals lose their water absorbing capability after some time, so they will need to be replaced. Refilling the media differs depending on the level of humidity in your area.

If you're not careful, the gels can also fall out of the syringe, in this case you'll have to remove what's remaining and replace everything via a Humigel replacement kit.

The compact design also makes it viable for acoustic guitars with smaller, or distinctly shaped soundholes, like those from Ovation guitars. Note that the cap is a bit thick, and might not fit inside tight cases.

The downside to its special media is that there's no easy way to check if it needs refilling. You'll have to push the strings to the side and pull it out gently to not damage its special cloth like exterior. Once pulled out, you can check if the OH-1 has shrunk and needs refilling of water.

The versatility of the OH-1's small profile makes it a safe pick regardless of the type of guitar you own.

Specifications

• Weight: 0.8 oz
• Suspension: Held By Strings
• Longevity: Long

The MusicNomad MN305 HumiReader Hygrometer, Humidity & Temperature Monitor is a great, no frills in-case thermometer and hygrometer. It comes in a compact size and shape that's similar to the MusicNomad Humitar MN300, which makes it easy to use and store if not needed.

Its main selling point is that it can actually rest in your guitar strings, giving you a more accurate reading of the humidity your guitar is experiencing, compared to room hygrometers. And more importantly, it's small enough to sit on the strings together with the Humitar, so you can get readings and humidify your guitar at the same time.

Aside from being soundhole mounted, this unit comes with a mounting holster, similar to the Humitar MN303, allowing it to be stored in the case. The holster has a 3M adhesive that lets you stick it inside a safe spot within a guitar case. Just make sure that it's positioned properly where it doesn't come in contact with your guitar.

In addition to being a soundhole and in-case hygrometer, you can also leave it sitting out in your room if you happen to need a room humidifier. It can also compliment any existing room humidifiers that you may have.

Holster with Adhesive - Image Courtesy of MusicNomad.

While this isn’t a must-have feature, the MN305 also comes with a reminder of the proper humidity level and temperature for a guitar.

It’s a huge help if you’re not used to having to humidify your instruments, because the unit itself will always remind you what the proper temperature and humidity ranges are for your instrument. Using a hygrometer also allows you to check the effectiveness of humidifiers, and the readings can also be indicators for refilling your humidifier.

The main downer is that it's one more guitar related gadget to worry about, which complicates guitar maintenance. But it is a necessary compromise if you want to better protect your instrument.

If you're looking for a versatile hygrometer that can rest on the soundhole or in-case, then this one is for you.

Specifications

• Weight: 0.3 oz
• Features: Humidity Readout, Temperature Readout

The MusicNomad MN306 combines their best selling products, the Humitar (MN300) and Humireader (MN305), in an affordable bundle.

Both of them made it to this list as standalone units based on their individual ratings. But getting them in a single package allows you to save some money, and get everything that you need to protect your guitar from humidity in one go.

Since they have similar form factors, use and maintenance is simple and straightforward. The Humitar MN300 is a soundhole mounted humidifier, with a special Humid-i-Bar sponge inside that's good at absorbing and releasing moisture without leaking water.

It is designed primarily to sit on the strings and humidiy the guitar right inside the soundhole. The Humireader MN305 is a hygrometer that is similar in shape to the MN300. It can also sit on the strings to provide more accurate reading.

More importantly, both of them can fit into a regular sized soundhole, so you get the benefit of a hygrometer and humidifier.

No leak Humid-i-Bar sponge

The MN306 bundle also comes with a mounting holster, which allows you to secure either the humidifier or the hygrometer inside a guitar case. The holster has an adhesive that lets you stick it on to an open area inside the guitar case, usually near the headstock support.

With this, you can reduce the extra tension that's being applied on the strings by just having one of them on the soundhole. It would've been nice if it came with two mounting holsters, so that both the humidifier and hygrometer can be mounted in-case.

Humitar and Humireader together - Image Courtesy of MusicNomad.

The downside to this set up is that you're complicating guitar maintenance with two new tools. But these tools are important if you want to make your previous acoustic guitar last long.

If you're looking for an affordable way to measure and maintain your acoustic guitar's humidity levels, then check out the MN306 package.

Overall

Specifications

• Weight: 3.2 oz
• Suspension: Sits in Case
• Longevity: Medium