delayed switch for co2 regulator

Projects General Guidance
1

I want to build a switch that makes it possible to use tanks of Co2 in a greenhouse without interruption. The problem is that when a tank runs out, co2 supplementation is interrupted until the tank is replaced. What I want to do is build a device that will turn on a second tank when the first tank runs out. Here is how it will work:

In order to keep Co2 at a set level in the greenhouse, a controller is used that turns a regulator on and off. It triggers the regulator to turn on when levels fall below 1400 ppm and off when they reach 1500 ppm. This only takes a few minutes. So if the first tank is on for more than about ten minutes, we know that it is empty. That is when the backup tank should be turned on. So I need something that measures when a circuit is active, and then turns on a second circuit if and only if the first circuit has been active for over ten minutes.

The Co2 regulators are triggered by a standard 110 plug.

I am new to building with arduino and I know very little about it. I have built basic exercises from a book successfully. I have some parts and some money to spend on more parts. Can anyone help with this project or point me in the right direction?

Thank you in advance!

2

The 10 minute timeout should be easily achieved with an Arduino.

Do you want the Arduino to detect when the existing controller turns the CO2 ON and OFF - how will that work?

What sort of changeover valve will you be using?

...R

3

You could get advanced warning of a cylinder running out by using a load cell to periodically weigh it.
Enter the tare weight via a key pad or potentiometer and ask the Arduino to predict the next refill date based on the average daily usage.