Fiber to the pool
Up until recently my dad was technical head of a team taking care of a small campsite. The campsite has a small pool and a few years ago it had to be renewed because of new regulations. This resulted in the pool needing Internet so that the pool could be remotely monitored. And since I am my dad's Internet helpdesk he asked me for recommendations, especially after we updated the WiFi on-site two years earlier when the site gained fiber Internet. The pool hut is about 50m away from the nearest location with wired Internet, and the entire field is covered with WiFi. And using local Internet access was mandatory; no 3/4/5G data subscription allowed.
The first idea was to use WiFi, but the pool hardware only supported wired Etherenet so we needed to convert to WiFi or continue on with wired Ethernet. I couldn't find a device to convert from wired to wireless using modern hardware; there used to be off the shelf hardware that was a WiFi client and had an Ethernet port, but I couldn't easily find any anymore that supported 5GHz wifi and that I trusted to run 24/7 for at least multiple camping seasons.
So that left either copper or fiber Ethernet. Due to lightning concerns I wasn't to big a fan of copper Ethernet between a pool hut and the main building, even though there's also an electricity cable between the two buildings.
So that left fiber. I found an online shop that could provide us with:
HDPE conduit with a pulling thread
Prefab 4x single mode fiber cable with pulling sock and on each fiber on both ends an LC/PC connectors
Note that we're using single mode cabling, there is also multi mode but we don't use that anymore in new installs. We also went for 4 fibers so that we had two spares after using two to make an RX/TX pair.
To connect the fiber on both sides we needed to convert back to copper Ethernet because the pool hardware didn't support an SFP (needed to connect fiber to networking hardware) so we needed an Ethernet converter. On the network side we didn't have a free SFP port, so we also used a converter here.
The active hardware we got from one of the major online fiber equipment sellers and consisted of
2x 1G "Ethernet to fiber" converters (unmanaged)
2x SPF coded for the device above with LC/PC connectors
I think we ordered 50m of conduit and fiber. The most expensive part of the fiber was having the shop connect the LC/PC connectors (8x) to all fiber ends, which costed EUR 80 per side; the fiber itself was around EUR30. The conduit was EUR75 for 50m. IIRC we got the most simple media converters, they were around EUR30 each, for the SFP's I got two of the cheapest ones the supplier had for the shortest distance (<40km), I think they came out at EUR50 each.
Installation was simple as could be; my dad and his team of volunteers dug a trench from the pool hut to the main building as close as possible to the entry point of the existing fiber for Internet access, laid the conduit and pulled the fiber through the conduit using the wire. A couple of weeks later I passed by and connected the pool hardware in the hut to one side of the fiber using the media converter and SFP (note the number printed on the fiber and make sure you swap them at the other side to connect TX to RX and vv) and something similar on the main building side to connect the fiber via the converter and Ethernet cable to the LAN switch
I will see if I can get access to the original receipts so I can find the exact amounts, the current prices for SFP seem a bit high.