It doesn't have to be air. It could even be water. Call it hydraulics. If it was water, the system could be closed. The air does not have to exit into the tank. It could be exhausted. A closed hydraulic system might be something to think about.
With all of the things you have planned, an IDEC SmartRelay
https://us.idec.com/Product/Programmable_Relays.aspx They don't have a lot of I/O or Input/Output, but they can sport battery backup, an LCD display and an operator interface of sorts. These are programmable in "ladder logic" or a "flow chart" type of language. There is a downside of requiring a "development system" of sorts, so to get started is about $300. Various power options are available as well. You can and I have played around with the language for free in simulation. They may have an astronomical clock as well.
They might be able to offer you a huge bang for the buck in the long run. Daylight timers, automatic feeders, temperature control etc. might be better accomplished with a few of these SmartRelays. They are basically tiny PLC's or (Programmable Logic Controllers)
Since your building and starting from scratch, now is the time to think of that "ultimate system". You can use that framework and add/subtract as you see fit. A good reason of building in this fashion is that when your building, your anticipating future expansion. It may cost very little to add a "hook" for an option now than to re-design it later.
When you use standard building blocks, generally the reliability goes up.
I have a source for outdoor enclosures, but your not there yet.
Industrial control panels are usually built using DIN terminal blocks, DIN mounted power supplies, DIN relays etc. This is a "T" rail system that makes control panel construction more like an Erector set. Stuff is more expensive initially, it's easy to troubleshoot and it's totally re-useable. There is even plastic "wire duct" for raceways within the enclosure.
For instance, let's just say that you build a "dual pump interface". This could be a box that has power in, a contact closure enable, an alarm output, fuses etc. and you put it into a DIN mounted case. So, when you want to add pumps, you grab a few of these interfaces and your SmartRelay, a Power supply and your off. Just connect and program.
When I was working in a laboratory, I made things that were still around after 25 years. The stuff I made was modular and fixable and did not have a single purpose.
An example is a temperature controller.
1. 120/240 is an option - wiring
2. Two fuses were always mounted - one or two was used (120/240)
3. A separate over temperature monitor was optionally installed (room on the front panel)
4. There was a small toggle that disconnected the heater output using a relay. (same relay was used in the overtemp monitor)
There was the ability to wire a ON/OFF/(ON) switch here for power drop out.
ON - Output contactor was enabled
OFF - Output was off
(ON) - Resets the drop out relay
5. The output relay state indicator.
6. There was a small toggle that changed the setpoint to zero or enable.
7. there was a toggle that changed the setpoint to internal or external
That was he ultimate controller. The hooks required were the connectors, a 240/120 control transformer, and an output contactor, an extra TC input hole and a relay socket and some attention to wiring.
8. There was a configurable connector on the rear panel
The fancy controllers (SmartRelay) won't get you anywhere unless the simple one works.