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 fan-tastic!
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]

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.

[OldTimerJustStarting]

Understand and agree. I have eight sensors set up in “strategic” locations trying to get in front of these issues but it is a challenge. I am still not happy with the dehumidifier I’m using. I wish I had the knowledge to set up automation but for what I am dealing with it’s probably overkill but would certainly make things a bit easier. I am just using WiFi and across the counter components. It took two days to calibrate the sensors and that is even the “test lab equipment quality” items I have…

[Bluey]

I no longer measure temps or humidity under the lights. I have great air movement above through and below canopy so only measure the rooms environment, 24⁰C at the start of flower and slowly lowering it to end around 22⁰C.to 21⁰C

You can use Google home to run your scripts or alexa or one of those other ones. I don't use those but I did sync them across to google home and they seem to work there also.

The sensors I use for automating aren't very good and require calibration every week and every change of temp or RH. That is a bit of stuffing around getting that right. It's a PITA.

I'm yet to flood my room 🤞