Humidifier at back of fan [DON'T DO THIS - DEAD GROBO]

I’m having issues with getting the right humidity levels inside my Grobo, being the humidity too low. The only way to adjust it is to directly place the humidifier at the back of the Grobo, pointing towards one of the fan intakes. That way, I’m getting some mist going inside the Grobo and the humidity level is successfully raising. Does anyone know if the mist is going to eventually damage the fan?


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I have had success with a Tao Autohumidifer sitting on top of unit blowing to the back. I also have a tower fan on the side running on medium setting to keep air circulating.

@Luandri you need to be careful how concentrated the plume of smoke entering the fan is.

Here’s a pic from another member that tried this in the past, this was working well at first:

Here’s the result some weeks later: Dead Grobo

My humidity hovers between 20-30% most of the time, it hovers around 40-50% when there are a lot of leaves/buds growing. I try to raise it to about 40% or more when possible but that’s not always possible. I’ve perhaps observed a slightly lower yield due to that.

If the roots are not healthy then more humidity helps but I’ve found that maintaining the perfect amount of humidity is nice-to-have rather than need-to-have. The roots are always in water, so (my understanding is that) as long as the roots are functioning that should make up for most of the difference.

Here’s where I position my humidifier and try to leave it on the lowest setting as not to refill it too often, it raises humidity from a starting point of 15-20% to about 30-40% usually.

I point the nozzle of the humidifier toward the wall instead of toward the grobo. There is AC and fans behind where the pic is taken to push cold air into that corner behind the grobos; that helps break up the mist a bit too and the lower temps make it easier to maintain the RH % btw.

Placing a container with some water inside the grobo might help raise humidity but I’d still be cautious not to overdo it. The biggest thing that helped me to raise my humidity was keeping door and windows to the room closed and the temperatures down to a “comfortable cool”.


Thank you. Did you have problems with high or low humidity? What type of fan did you buy that fits into the Grobo?


Thanks for sharing this very useful tips. I’ll follow your example and see what happens :slight_smile:


what’s not visible in that pic are these fans:

and this a/c unit a couple of feet behind the fans

I channel the AC under a table that’s been fitted with a skirt to force the cold air from the AC in behind those fans, which push it through the mist into that corner. I used to deal with overheating issues (lights going out, root rot) but since doing this have had much more success.

The biggest thing to control is the room itself if possible, not just the grobo.


Found it on amazon! It is really nice comes with 2 power banks that last about 18 hrs on medium fan setting. When one battery runs down u have one to swap out with. I can show u some pics of it inside if u would like. I also as mentioned before have a tower fan outside of unit to help circulate air and it helps with resovoir temps too! @Luandri

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Thank you! I’m going to buy it now. And yes, if you don’t mind, I would love to see pics of the inside of your grobo set up.

Thanks again!

Inside and out! The fan at the top was something I was testing out! The one one the bottom is what I was suggesting to u! I have another one on order to hang up top like the one on the bottom.


This is super useful, thanks again for sharing. I placed an order for both fans and humidifier:)




  • (Be Careful where You Place The Humidifier): :electric_plug:





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