I have been running a raspberry pi for an internet connected weather station since 2014 and I have found it to be very stable. I have run that pi for over a year at a time without issues. The top three things I would consider for pi stability:
1: Power. You will need a power supply with a decent current rating, especially as you add to your GPIO as your setup grows. The Raspberry Pi foundation folks recommend 2.5A for the Rpi 3. But another consideration is investing in a UPS to deal with power outages. Going a step further would include a UPS monitor like Network UPS Tools (
NUT) so your pi can automatically shut down during a prolonged outage.
2: MicroSD card: These cards were originally meant for storage not running an OS. Find a reliable card (ie Sandisk or Samsung) from a reputable seller (sorry, no eBay $0.99 specials!). They both sell cards that are waterproof, xray-proof, temperature-proof, and magnet-proof. While all these designations are not strictly necessary, I think that the more reliable cards are worth the small premium. You don’t need a ton of space for reef-pi, I have used less than 2GB on my card and that includes a bunch of stuff I could delete
3. Network connection: Most of us run our pi’s headless. I think this improves reliability as the GUI isn’t used but it also means that a solid internet connection is important. The old wifi USB dongles I tried on my raspberry pi 1 were not reliable enough for my weather station so I only used Ethernet. The modern pi boards have a more robust built-in WiFi, and perhaps suggestions like
@Ranjib made regarding resetting the connection nightly can make it even more stable.
There are a variety of other open questions related to our reefpi project that are currently unknowns. Just how reliable are the temp sensors, relays, optical sensors, etc we are all sourcing from different places during prolonged usage? I recommend redundant systems for critical components like temperature