# Grow controllers? Do they exist?



## Squatchbud (Dec 26, 2018)

Ok guys, as well as my horticultural interests, I also keep coral reef aquariums. As I was thinking about my reef hobby the other day, it occurred to me that I have a controller on my reef that monitors water parameters and then automatically turns on and off different pieces of equipment in order to keep my parameters within the desired range I want. Do they make a unit like this that could measure humidity in a tent/grow room? A unit that could monitor both temperature and humidity would be awesome. If said controller could then switch on or off humidifiers, dehumidifiers, and fans to maintain the desired levels. Does such a controller exist? If so, how much do they go for and what are they called?  Thanks.


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## Growdude (Dec 27, 2018)

https://growgps.com/products/chhc4i/
Controls Temps/humidity and Co2 level


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## pcduck (Dec 27, 2018)

https://www.plantlightinghydroponics.com/products/atmosphere-controls/master-controllers.html


The one I use controls co2, temps, and humidity


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## Squatchbud (Dec 27, 2018)

PC, how do you like it? Is it worth the cost? Is it reliable? I am considering one, but I wanna hear from people that use them first.


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## pcduck (Dec 27, 2018)

Definitely needed if running co2.
Not so much if not, but the plants seem to enjoy the stable environment.

I like mine.


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## Squatchbud (Dec 27, 2018)

Good to know. After I get a grow or two under my belt and start using CO2, I'll have to get one. Thanks.


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## Growdude (Dec 28, 2018)

Is that place still in business ?
Still buy from them?
They still owe me.


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## pcduck (Dec 28, 2018)

@Growdude 

I'm not sure if open or not. I haven't had the need to purchase anything lately from them.


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## Rjb (Jun 28, 2019)

I no its not really what your asking but what about the northern lights grow boxs


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## stinkyattic (Sep 9, 2019)

There are also controllers to monitor and automatically adjust reservoir pH. I use these at work for a flow through wastewater treatment system, and at my previous job for industrial fish tanks. Yes there are industrial fish tanks, it's a thing, and I have swum in them (with the fish, no less, eww, no wetsuit, no scuba gear, absolutely disgusting) more times than I'd like to remember. Seriously it's the stuff of nightmares and definitely violates OSHA confined space entry regs. Worst job I've ever had. And I've had some doozies.

The basic principle is you've got a probe in the tank, which needs to be cleaned every couple days, hooked to a controller (preferably also to an alarm) where you set high/low parameters. Then the controller outputs to a dosing pump which controls a feed from a chemical reservoir. 

Since you probably already know which way you'll drift, you choose either pH up or pH down. A two pump system is much more costly and a bigger PITA to operate.

Let's say your res drifts down over time. You'd choose pH up, and set your parameters to dose when the pH falls below say, 6.4, and to shut off at 6.8 (this is just an example). When the probe input to the controller falls below setpoint, the controller calls for some caustic and activates the pump. Usually this would be a peristaltic pump which is quiet and low flow. It pumps in some solution and shuts off when it hits the setpoint.

I have seen these systems fail catastrophically resulting in Very Bad Things. They need to be cleaned and inspected daily, and you need some type of constant mixing in the res to make them accurate. 

For a home grower it's more expense and headache than it's worth. You'd see a setup like this in a larger commercial operation with a daily inspection log to confirm someone has been wiping volume off the probe and calibrating the controller.


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