Daddario GH Humidifying System

The poor rating is based on what I think of the product in it's original form and not my intended use, for which I think it's great.

I've had one of these since many years and ordered one more since I have one more guitar now.
The general idea behind the product is good, even though it's not revolutionary. The main issue with the product (and others like it) is that the sponge can hold very little water.
Depending on circumstances you will have to wet the sponge at least once or twice a week, IME.

If you intend to use the sponge bundled I'd suggest you at least get the "pro" version instead, that can hold more water, or even look at another product.
However, I didn't intend to use the sponge and use it with orbeez/water pearls instead (it's quite an easy mod), so I bought the cheaper alternative.

So, the plastic "case" is, IMO, useful, since it is easy to modify for use with orbeez and it can sit in the sound hole while the guitar is in the case, so you don't have to mount it to the case itself or worry it might scratch your guitar.

Basicly it is a sponge ...in a black plastic container.....sometimes simple things just work....

Soak the sponge in water....
Rinse it out so that it does not dripple any water....
Put the sponge back in the black plastic containers....
Put the lid on it
Dry the container in case it got wet in the process.
Put the container in the body of the guitar the top resting on the 2 of the middle strings holding it in place.
Recheck the sponge to see if it gets a little dry.....if so repeat the process...

Works best when the guitar is in its case....

I bought this humidifier because my guitar is always in a stand and the humidity levels were about 30%. I already knew that this humidifiers work best in a closed environment, however I preferred to risk dryness of my guitar instead of having it perfectly humidified in the case but playing less with it. For that reason my expectations were quite low with this product. I can assure you that I was wrong. If I damped the sponge early morning It will keep the moist until the next day and, because the humidifier was inside of the body of the guitar I'm certain that the moist was absorbed first by the wood of the instrument and only then was released to the environment. There are several good point in this humidifier: it's easy to remove; it doesn't need expensive refills (deminiralized water is all it needs); it doesn't touch the wood of the guitar; it is inserted deep into the soundhole.