Leak in the floor drain

[RecurveArcher]

We bought the house 5 years ago, the floor drain never worked, seemed clogged or plugged; it's a 6" circle, 4" deep with the pipe coming to the side of the hole, concrete in the hole has broken off somewhat. We installed new coping last year, had rust holes patched in the walls, and the pool re-painted. While empty I blew some air through the floor drain to see if it was clogged, didn't see anything noticeable come out, but it got it cleared. After filling it, the floor drain will work, but lets in some air when that value is open, so I assume there's there's a leak/break in the line somewhere. We also have some water loss here and there, and I assume that's the cause as well. I generally keep the value to the floor drain closed so as to not make it worse and not bring air into the lines.

What are the options to address this? Despite the air, it was super nice having a working floor drain when closing the pool last year vs. trying to drain it via the skimmers while keeping it air tight to maintain the seal. So, it's nice to have available, but the leaking water is a hassle and I'm concerned about it getting worse or letting contaminants into the water.

I'm not going to dig/cut out to install an new pipe; we just had the work done last year and without knowing where it's broken, I'm not paying that much money to fix it.

Do they make oversize drain covers, like the flat ones you can use in sinks, but big enough to place over the drain? Guessing not, and I doubt it would seal/hold the same way as in a sink.

Can you feed a smaller flex pipe down the 2" and somehow seal it at both ends?

If nothing else, can I make a big ball of epoxy putty and just stick it in the opening in the drain to seal it off?

Other options?

 

[reggiehammond]

With it valved completely off - do you still lose water? The prevailing wisdom here that I've read is mostly the main drains do very little, especially with the floor cleaning abilities of modern robots. If you don't leak while valved off, then I'd just ignore it forever!

 

[RecurveArcher]

Yes, it still loses water with the value off. It's inconsistent, sometimes it seems to noticeably drop for a few days, but then can go weeks with minimal difference. I top it off maybe once per month; it stays covered so we lose minimal water to evaporation. My assumptions are that the inconsistency in water loss could be ground shift or saturation level; ground is dry it leaks more, we get some rain and the ground has more moisture so it doesn't leak as much. I don't really know for sure. It's not significant now, but a small annoyance and a little extra cost to replace CYA and salt when adding more water, but not a big impact currently; I guess I mostly want to have a plan in case it ever gets worse and starts leaking a lot, or get an idea if that's a risk leaving it alone and better to block it off sooner than later just in case.