What size dehumidifier for grow room with 4x4 and a 5x5

Hello guys and gals, I’m currently looking for a dehumidifier for my grow room I have a 5x5 and will be adding a 4x4 tor a veg tent. I really just want something that will last and actually work, I asked earlier in a previous post so I don’t mean to be redundant just tired of wasting money as the market is saturated with shorty products. What size dehumidifier will I need? Any suggestions on particular ones that they have experience using and are happy with the quality? Thanks everyone and enjoy the rest of The Weeknd !

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A 70 pint can get those sizes down to, and hold it near 35-45% without concerns


That’s what I figured. Anyone have any suggestions for good 70 pint dehumidifiers that will last?

hOmeLabs 4,500 Sq. Ft Energy Star Dehumidifier for Extra Large Rooms and Basements

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I’m looking at this one it’s a 50 pint. Is this big enough or should I stick with a 70?

It’s going to depend a lot upon how humid the region you live in is, and how many plants you’re going to have at a time.

We have very humid summers where I live. I have a spare bedroom with a 4 x 6 closet grow, a 2 1/2 x 5 tent, and a 2 x 4 tent. I do on average 10 plants at a time between the 3 grow spaces.

I started out with this 70 pint a day GE unit I got at Home Depot. It can do a decent job early in flower when I’m only trying to bring the grow spaces down into the upper 50’s, but it cannot come close to what I need when I’m looking to get it down to 45% or so later in the grow. Another thing to keep in mind is that it adds a good amount of heat in the room.

So next I bought this 95 pint a day unit by SoleAir. This one can bring the humidity as low as I need really quick. She’s a beast, but it puts out a ton more heat than the 70 pint, and it costs a tremendous amount more in electric as well.

Finally, after struggling one way or the other with temps and humidity for a few years, I bought a DIY mini split ductless unit for the room. It’s 18,000 BTU’s, and has AC, heat, and dehumidify modes. Believe it or not it’s less expensive to run than the 95 pint a day unit. I got it from HVAC direct. It’s shipped fully charged with freon, and has quick connect fittings on the line sets to make installation really easy. I would suggest something like this for anyone with a decent size grow room. I wasted so much money on window units and portable AC’s the first few years, only to still have the same issues, or even make new ones. Everything has been much easier since the day I got the mini split.


How much did one of those run you? If I read that correct this is an ac that also controls the humidity. I run an ac In the room as well that’s hooked up to an ink bird controller. My electric bill is 4/500 a month as is I don’t want this to get way higher when running the 4x4 and a dehumidifier

This is apace right now with my 5x5 and 2x4. Spare bedroom, small bit I’m hoping to get the most out of it I can. I’m in New York

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I got a refurbed 35 pint GE dehumidifier for about half the price of a new one. Have had zero issues with it. Take the time to look around and you’ll probably save a lot of money.

I’ve been getting good harvest just from the 2x4 and 5x5 so I can’t wait to have a solid perpetual harvest going with some good mother plants with great genetics

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I’m gonna start pheno hunting once I’m all set up.

I think it was around $1,400.00 including shipping, but I definitely went way oversized with the 18,000 BTU. I’m sure the 12,000 would have been fine and I think it was a couple of hundred less.
It’s far more useful in the summer when you need to control heat and humidity at the same time, but it’s also nice to have the heating option in the winter. One of the best features of it is that it makes the room colder in dehumidify mode instead of producing heat like standard dehumidifiers. That also can be the one drawback about using it to dehumidify in the winter, but it also does a decent job drying the air when it’s on the heat mode.
So basically, I get a lot more out of in the summer, but it has it’s uses in the winter as well.

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I wish I would have known about this a year ago cause I easily spent that on all of the equipment I have to control environment. I’ll def be getting one of these eventually just don’t have the funds to justify it at the moment. Something to look forward to though for sure. I spent 600$ just on my ac. Which works great no complaints just saying though all in one system is legit.

This is the dehumidifier that gets the most use from me. Its in my 4x8x6 flower tent with a portable ac unit also pictured below. Both run off inkbird controllers and for heat i have my HVAC ducts tied into the tents which i can hookup as needed to help manage temp if needed. Moreso a fail safe than anything

@matty777, I hear you! I spent a small fortune over the years trying to keep temp and humidity in check, and I did all kinds of work, like cutting holes in my walls, ceilings, and floors to vent the portable AC units when a window wasn’t available, or to exhaust the grow spaces out of the room. I feel like I tried everything, and every time I got one issue worked out there was always a snag of some sort or a new problem would arise. Even with the big mini split I’ll have an occasional tough time, like one tent will still be a bit too hot while the closet will be right on the verge of too cool, but for the most part it solved my biggest problems for sure.


I have a 4x4 with a maximum of 4 flowering… considering the soaked pots and transpiration rh, I personally find the 70pint to be meet the mark. It’s only on extremely rainy days of 100% outside humidity do I find the rh inside the tent to be off by 8%. The unit was outside the tent all spring summer and fall…and venting miniscule dry air in --until last week… it’s now inside the tent venting all its own heat back outside the tent except residual blow by, and that makes for perfect in the winter where i need heat during lights out…also, My tent is in a shed. Now you’re going to be flowering in a 5x5 and i think you could easily do it with the 70pint… The other tent is veg, and will easily regulate with logistic fan, and humidifier.
Where can you dump the overall heat is the question.
A 70pint cost 60 a month if ran nonstop

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This is likely the hardest juggle…fans, exhaust, dehumidifier… humidifier…like playing tetris until you hit the perfect moment, and sware if you stand still and dont breathe everything will remain…lol… the mini split idea is still calling my name


Depending on the room size…a 70 pint will work nicely. Especially if you have a drain to allow for constant use without having to empty it.

I have one in 3/4 of my basement with 3 4x4s… Veg, flower, drying tents.

No issues.

A 35 pint under the new ratings would have been called 50 pints not long ago. I use a 35 pint GE refurbished dehuey in my lung room and it keeps the humidity wherever I want it. I was given a brand new 50 pint smart dehumidifier today so I may try that out. But the one I’ve been using was $105 online and works like a charm.

Did I over defoliate. I’ve been having so much problems wirh the damn humidity and I really should have done a defoliation right before I flowers but these girls really juyst started shooting up and I was worried about space so I flipped them to flower 2 weeks prior to what I had planned. So they are about a week since the flip and I defoliated the hell out of them. Did I over do it?