I have a new above ground pool I just had built. At my last house, I had an in ground pool, and on the edge of it I installed a $70 device that uses a float valve to control my garden hose and fill the pool to the proper level when it got low.
I've read here, and I agree, that a drawback is that if can mask water leaks, though in the case of an above ground pool, I'd think I could see a leak if there were one.
Nevertheless, the real reason I got it wasn't to auto fill when needed, but to prevent overfilling when I forget to turn off the hose. So basically I only turn on the hose when I think the pool needs water, then I check back an hour or three later to see if it's time to turn off the hose and if it slips my mind until the next morning (which doesn't happen often, but has more than once to my supreme annoyance of filling the pool to overflowing and wasting water), then no harm done; it stopped flowing at the proper time.
Anyway, I still have the device and I'm thinking of installing it by clamping it to the top of my pool wall. My other problem is that my pool is more than 90 feet from the closest hose bib. I hate dragging that much hose that far, back and forth. And I don't want to leave that much hose across my yard all the time. (For one thing, it would interfere with lawn mowing.) At my last house, my hose bib was just a few feet away, and was on my patio, so I never had to deal with leaving a hose in the grass.
My idea is to dig a more than 90 foot long trench, and bury a PVC pipe in it, and on the hose bib side, have a threaded adapter and maybe a short hose that can connect to my faucet when I want to fill the pool. This also would allow me to use the faucet for general yard work when needed.
On the pool side I'm think of having the PVC emerge from the ground, go up the pool wall, and have another threaded adapter so that I can screw it into the float valve device (no hose needed). Maybe I should install a union there to make it easy to connect and disconnect the device when needed.
I guess I don't have specific questions, but I just thought I'd pass these ideas by this forum, as I just kind of conceived of these ideas on my own, as I've not read anything on the subject, nor do I know anybody who's done it. I also have never dug a trench like this, and don't know his hard it will be.
But I've seen my sprinkler system installer guy dig a trench, and it didn't look all that hard, but he had a special skinny shovel that made it easier to dig a skinny trench, so I'm thinking of buying such a shovel. I suspect the price of the shovel will be a lot less than hiring somebody to dig the trench.
Anyway, if there's an easier way to accomplish my general mission, I would welcome any other ideas on the subject, but maybe my idea is already the simplest.