I did it, but I’ll be honest, “realistic” depends more on your tolerance for chaos than your skill level.
The physical work is one thing. The mental load is another. You’re suddenly the project manager, scheduler, inspector chaser, parts runner, and problem solver. I hired out excavation and shotcrete because that’s not something you want to learn on YouTube. After that, I handled plumbing, equipment pad, and some of the finish work.
Where it gets real is sequencing. You can’t just wing it. For example, I had to pressure test all my plumbing lines before backfilling, and I’m glad I did because one joint had a tiny air leak. Fixing that early saved tearing up concrete later. Same with the equipment pad. I oversized it a bit so I wasn’t cramming my pump and filter together, and I paid attention to head loss so my filter pressure landed where it should once everything was running.
Time wise, whatever number you’re thinking, add 30 percent. Weather, inspections, backordered fittings, random things like realizing you forgot a conduit for future lighting. It stacks up.
If you’re comfortable learning as you go and you don’t mind weekends disappearing for a few months, it’s realistic. If you need clean timelines and low stress, a hybrid route is usually smarter. The first swim though, knowing you built it, that part really does hit different.