Temp and hygrometer accuracy


I’ve been running my Growhub for a coupla months now and yesterday I installed an AC Infinity Cloudline T6 with the Controller 67 for temp and humidity control.

I’ve placed the AC Infinity probe right next to the NIWA Grow hub probe (both just above the canopy) and I’m seeing the following

Temperature difference: 1.5 to 2 degrees (with the NIWA probe reading HIGHER then the AC Infinity probe)

Humidity % difference: Basically 5% (with the NIWA reading LOWER then the AC Infinity probe)

Anyone else got more than one temp/humidity probe and observed similar differences?
The temperature diff I can live with but the humidity diff is a little concerning if I was relying on the NIWA to control the humidity via an attached device like an in-line fan.


I have numerous hygrometers around (I use most of them for curing) and they all read slightly different. I just take an average of the readings and use the offsets on the Niwa app to dial in the Grow Hub.

If only the grow hub triggered the exhaust fan based on humidity as well as temp, you wouldn’t have needed the AC Infinity system. I might have to go that same route soon as well.

Thanks brotha! Yea I’m basically averaging the two but I’ll tell ya I’m leaning towards the AC Infinity probe being a lil more accurate than the NIWA probe

I might pull the CoPilot I have in my veg lab and drop it into the bloom lab for a week or so to have a 3rd data point to see what’s what. The copilot has been very accurate (at least as compared to another AC Infinity unit I have for veg (Controller 76 to control heat/humidity)).

Have a great day! :pray:t2::call_me_hand:t3::peace_symbol::green_heart::fire::facepunch:t2:

I also go with what my AC Infinity Controller UNC529 is reading since it doesn’t have the option to adjust the offset like the controller 67 or the 69, so I find the UNC529 to be more accurate. Then adjust the offset on the Niwa to get it as accurate as possible to the ACI controller. You can also place an analog Temperature/hygrometer inside your tent, wait 30 min or so and then adjust you controller and Niwa accordingly. The reason I say analog is because I’ve bought different digital ones of different brands and the readings are always different from one another. they should be reading the same since they are in the same enclosed environment, but they don’t, so try analog.

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Try plugging the ACInfinity into the GrowHub. Assign the outlet to “Dehumidifier”. Set humidity parameters for your recipe.

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I do the same except for temperature control, I assigned the outlet to “fan.” Remember to set the ACInfinity to “Max,” and let the NIWA sense the humidity and cycle accordingly.

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The Niwa sensor are better and more accurate than the AC infinity sensors. I have a Niwa, 3 different AC infinity, 3 Ink Bird humidity and temp controllers. Also a bunch of hand held ones and they are all within 2%-3% of each other, except the AC infinity. My AC infinity is actually up to 10% inaccurate. Trust the Niwa before the AC infinity. You can do an average of the 2 but in my experience the Niwa is more accurate.


Thank you! This worked for me as my humidifier is not able to be turned on/off by the Niwa. I was thinking of different combinations using the outlets and came across this while seeing if anyone else had tried it.