Rio to supply constant 12VDC

We have an application where one less power supply would be helpful. In our case, could we use the Rio DC outputs to constantly supply (24/7) 12VDC to one of these, and then add another separate one ~6 times/day for 3 minutes on a timer set in Node-RED? (meaning two separate 12VDC units running independently)

Where is the 12VDC power source coming from?

My hope (perhaps misplaced) was that the Rio’s output would handle this. But in hindsight, I think we could take a regular 12V power supply and split it into 3 outputs so that one goes to the Rio (which requires 10–32 V DC) and one goes to each air pump.

That could work, you can route the power for the pumps through the RIO DC output to switch them on and off.

Yes, use one 12VDC supply with enough Amperage and you should be good to go.