Grow Environment

[OldTimerJustStarting]

My question I hope is simple. I am unable to decrease the humidity inside my grow tent any lower than the outside environment of the grow tent area. I do have a dehumidifier inside the tent, temperature does not seem to be the challenge, but the humidity is causing me to lose sleep. I can only lower the humidity to the same as the humidity outside the tent. What can I change? I have a 2x4 Vivosun tent with current technology light and twin fans inside. Any suggestions or recommendations will certainly taken seriously.

[Rwise]

I would say put the dehumidifier in the lung room (even if it needs to be a bigger unit), I think you'll get better RH control.

[Gingerbeard]

What is the humidity?
Winter months are coming. I don't know where you are, but our humidity is going to drop when it cools off. I'm in the same boat with being a slave to the environment. Winter months are always better for my tent.

[OldTimerJustStarting]

I’m in Ohio and the area outside the tent is 75%, inside the tent, 75%. It tracks within a %. I have calibrated with test equipment and have test equipment inside the tent to validate readings. I doubt I can control the outside tent area as I am running a whole home dehumidifier inside the area and a small Vivosun dehumidifier inside the tent. I am considering installing a one way valve at the exhaust port of the tent to see if that will help.

[Gingerbeard]

This is not a solution to your problem. Rather, a way to keep humidity down at certain times and a word of encouragement.
Your tent will be the most humid right after you water. Make sure to keep it well-ventilated when the tent is closed, after watering. And use plenty of fans. Fans are fantastic!
75% is not horrible. I'm 1.5 miles from the Pacific Ocean and get decent results at 75% and higher in the summer.

[OldTimerJustStarting]

Thanks… I would have responded earlier but I was unable because I was not logged on … go figure … just to hear an old timer fussin at this iPad cause I couldn’t figure out why I couldn’t reply … jeepers

[paintslinger78]

Curious what the temperature is inside the tent and outside the tent. Depending on what stage of the grow you’re in you could adjust the VPD with the temperature.

[OldTimerJustStarting]

The temperature ranges from about 65 to almost 80… tonight, 68.8 temperature and 72% humidity. I use the VPD numbers, tonight right now it’s .7 and the plant is in the vegetative stage. The area outside the tent is 66 degrees and 67% …

[Bluey]

What make & model dehumidifier are you using?

Can you seal the room the tent is in?

[OldTimerJustStarting]

This is a Vivosun dehumidifier which is inside the tent and I checked it tonight when I got home from work (no, not retired cause I’m stupid) and no water in the dehumidifier

[Pyrokill]

Not sure if it will help your situation but I ran into an issue with venting the tent to the basement. It eventually kept the basement at a high RH until I ran a line to exhaust the tent to the garage. Just cut a 3 inch hole into the frame of the house and put a screen on it to keep the mice out. That move let the basement chill out and it's not been too bad anymore.

[OldTimerJustStarting]

Good thought… I’m hoping a flue thought will help, thanks

[Bluey]

You need a new dehumidifier. Depending on your environment and number of plants and size will determine minimum size.

I wouldn't go for anything under a 50 pint/day with a drain and controls to set the RH level. If you don't have a drain in your lung room you can sit it on top of a decent size plastic trash can and let it drain into that.

I run a 100 pint/day and with 5 large overgrown plants jungle style in a sealed 620 cu ft room with 2 air conditioner at 22 to 24⁰C and I struggle to get it below 40%RH late flower...but I can keep it about 50% at their peak in flower.

[Bluey]

I couldn't find a decent wifi one here so I use a PowerPoint to control the automation. Lots of them you can't do that though, when power is lost you need to turn the unit on manually which is no good for automation.

[OldTimerJustStarting]

Interesting…do you mean PowerPoint as in the Microsoft product? I attempted to use a Digiten, model DHTC-1011 … which can remove the power based upon parameters but I find you are correct, when the power comes back on the unit does not automatically come on …

[Bluey]

PowerPoint as in wall socket you plug the cord into.

I have them connected to my modem/router via wifi and run scripts to control everything environment related inc the lighting and fertigation.

It's not fool proof but works perfectly 99% of the time.

It took a while to find suitable air conditioners and a decent dehumidifier I could run that way rather than rely on their own inbuilt thermostats & hygrometers to control the environment separate from the automation. The hygrometers in humidifiers & dehumidifiers are very very inaccurate and typically only hold accuracy in a very narrow temperature range and not for long. I use a number of sensors to measure the environment to try and maintain accuracy which was the biggest challenge barring power outages.