Trying to find the right dehumidifier for a 5x5 grow tent.

Sorry for the double post. Posted in the wrong section initially.
Hey folks,
Looking for a dehumidifier that can treat a 5x5 tent effectively. I'm on a budget though, no more than $75. I found some used ones in that price range, but that's an as is sale. Do I need to treat the grow tent or the room the grow tent is in? The room is roughly 12x12, but it has a built-in window A/C, which has humidity usually at 50-55%. Lights out, though, my tent quickly rises to high 80's. Lights on in the tent, it's 45-55%.

I'm not sure why it goes so high. I have a 6inch fan venting outside at full speed, and a 4 inch fan venting into the tent at full speed, air which has been treated by the A/C.

For the time being, I have a space heater in the room with the A/C on. I was able to bring the humidity down to 55% (and dropping) while the temperature hasn't risen too much. That space heater is probably 2400watts though, so not a long term solution.

I'm also looking at this: https://www.amazon.com/LUOYIMAN-Deh...07867SVJH/ref=cm_cr_arp_d_product_top?ie=UTF8 but it comes with a UV light that treats the air, I'm not sure what wavelength it is and if it would bother the plants at lights off, were it in the tent.

I put a home security WiFI camera in the tent that has night vision so I could figure out what was going on without bothering the plants. I was hoping it was just peaking high 80's right after lights off and then dropping back down, but nope, I was able to confirm it wants to stabilize in the 80's. I have my hydrometer just above plant canopy.

Any suggestions are appreciated!

Are you venting in to the room the tent is in? Does that room vent from outside? If your lights are on during the day when sun is out the dew point drops making the ambient air drier. Also I doubt the ac kicks on very much at night when lights are off. Try running lights at night so ac will cycle more evenly during day night cycles. And putting ac on low setting. Low will remove more moisture.

Rakin said:

Are you venting in to the room the tent is in? Does that room vent from outside? If your lights are on during the day when sun is out the dew point drops making the ambient air drier. Also I doubt the ac kicks on very much at night when lights are off. Try running lights at night so ac will cycle more evenly during day night cycles. And putting ac on low setting. Low will remove more moisture.

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Thanks. I thought of that as well. The reason I run the lights during actual daytime, is because of a few reasons... I don't want to risk any of that HPS light being spotted from a window. Also, my wife and I need to use that bedroom during the day, there's a bathroom attached to it. I don't want to risk upsetting the dark cycle from light leaks coming from other sources as we go in and out of the room during lights off.

To answer your question about ventilation, here is a graphic I made couple weeks back that sort of explains everything better than I can type it.


If I were to switch the light cycle, would I be able to do that during this grow? I don't want to stress them out too much. Next grow, I'll definitely do it, but I'm kind of nervous about switching them over now at 19 days flower.

How far into flower are you? I’ve changed schedules in the middle of flower. You can do it all at once or spread it out over several days. You just don’t want to cut a dark cycle short doing so.

So you do have the exshaust venting to outside as outside the house? Where is the fresh air for the room coming from? Rest of the house? Another vent hole in the room?

In the long run. Your going to find that the one with the largest holding tank, OR a direct drain to a condensate pump as being the best...

Craig's list BUT, sanitize it before use...

I'm actually on my way to purchase a never used dehumidifier 70 pint. https://www.amazon.com/dp/B073VBWKJZ?ref_=Oct_CABSellerC_267557011_0&pf_rd_p=f3070278-86ec-5ab7-b6f0-5ff975e195bb&pf_rd_s=mobile-hybrid-8&pf_rd_t=30901&pf_rd_i=267557011&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=RMN1PK218BTM2R8A5H8R&pf_rd_r=RMN1PK218BTM2R8A5H8R&pf_rd_p=f3070278-86ec-5ab7-b6f0-5ff975e195bb

70 bucks!

Rakin said:

So you do have the exshaust venting to outside as outside the house? Where is the fresh air for the room coming from? Rest of the house? Another vent hole in the room?

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Fresh air rest of house / room the tent is in. Exhausts outside as in outdoors

gjs4786 said:

Fresh air rest of house / room the tent is in. Exhausts outside as in outdoors

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For small grows I’ve always just vented into the room and then purge the room with fresh air every now and then. Easier to control entire environment that way

gjs4786 said:

I'm actually on my way to purchase a never used dehumidifier 70 pint. https://www.amazon.com/dp/B073VBWKJZ?ref_=Oct_CABSellerC_267557011_0&pf_rd_p=f3070278-86ec-5ab7-b6f0-5ff975e195bb&pf_rd_s=mobile-hybrid-8&pf_rd_t=30901&pf_rd_i=267557011&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=RMN1PK218BTM2R8A5H8R&pf_rd_r=RMN1PK218BTM2R8A5H8R&pf_rd_p=f3070278-86ec-5ab7-b6f0-5ff975e195bb

70 bucks!

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Good idea. You won’t always need it but it’s nice to have when you do

Rakin said:

Good idea. You won’t always need it but it’s nice to have when you do

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I got scammed...the link I showed is what was advertised. Drove 40 miles for some no name pos Chinese thing. I wouldn't give her more than 20 bucks. I was/am so pissed. Hopefully what I got actually works somewhat.

A 30 pint would won't fine, you could put it in the tent if you have to but as small as the room is you could probably just sit it in the room.

Serverchris said:

A 30 pint would won't fine, you could put it in the tent if you have to but as small as the room is you could probably just sit it in the room.

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I'm just running a space heater on a timer and I have the active air ducting next to that. Right now the temps are 79 degrees and the humidity @ canopy is 39%.

I attempted to buy a nice dehumidifier but I took a risk, and ended up driving 40 miles out of town only for a woman to bait and switch what she originally posted. I'm on week three of flower so I think until next grow, I'll just run the space heater. I have it set to go on 5 minutes after lights off and and turn off 5 minutes before lights on so I don't overload that circuit, as that space heater is 1500 watts if I'm not mistaken.

Hopefully, the warm air isn't tricking me into thinking the air is less humid. Before the heater, I was running 70 degrees at 85-92%. I just run the AC at 60 all day down and it seems that I'm running a zero temp dif....77-80 at the tops day and night.

ive used this on auto for 12 months in a 4 x 4 and its been faultless so far.
Andatech Ionmax ION681 Dehumidifier

New on ebay about $160 aussie so be close to ur budget if in yankee $

Target had a Haier 30 pint on sale for $127 this week

So this is what I got from the lady selling the hOmeLabs 70 pint compressor unit that was retailing for like 185 new with 4.5 stars and 1500 ratings on Amazon. If you look on the box, it uses 150 watts and has a 3 liter holding tank. Amazon says 120 watts and 106 ounce holding tank. Each website has conflicting info. It's works via Thermo-Electric Cooling as opposed to a compressor. I have no idea how she could have confused this with a hOmeLabs. The model numbers on the box don't even bring up hits on Google. As soon as I said something about it being completely the wrong item, she said "we get stuff off pallets". So then I knew they were just people who go around buying storage lockers and Amazon returns and stuff. Sketchy people in my experience.

I'm testing it out in different areas of the house to see how it does. I tried it in the room the tent is in for a few days and the humidstat on it didn't change. I'll try it in my actual tent after I'm done testing it elsewhere. I only paid 20 bucks for it, and it's going for over 100 used on Amazon. But I wasn't too happy with that lady and she's lucky I gave her $20 lol

Thanks for your suggestions. I just couldn't afford anything over 70 at the time, and still can't, so I'll just be using my heater for now at night.

If you vent you can change humidity as the volume is far to great, if you seal everything you can now change humidity.

If a fan runs at 300cfm and you vent then thats a shit load of air you wont change by much

Kingrow1 said:

If you vent you can change humidity as the volume is far to great, if you seal everything you can now change humidity.

If a fan runs at 300cfm and you vent then thats a shit load of air you wont change by much

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Yeah exactly...It's being constantly refreshed in that tent. I don't want to buy fan controllers right now, and it wouldn't be practical to do it manually, cause I wouldn't be around every single time it needed to be done. I could put the fans on a timer but that'd take a lot of trial and error, my current grow would be complete by the time I figured it out. So that's why I'm going to stick with the heater on a timer and full power fans for now, because the obvious solution is to spend a fair amount on a dehumidifier which I can't afford currently but I should have one near the end or sooner after this grow. I need to focus on what I'm going to grow next, that's the hardest decision of all, takes full attention