gunite pool, lost 5 inches of water in 2 hrs?!??!

[patplh]

Hi, thanks to TFP, i have a crystal clear pool - but I was out of town for 5 days and when I got back, needed to use my polaris for the first time this season (we haven't had many great pool days and when we opened, we used the vacuum/skimmer to clean it out)...
So I turn on the polaris and the filter and it goes happily through the pool. We go out for 2 hours while it runs and when I got back, the water level dropped 5 inches to below the skimmer and the filter was running with no pressure and the polaris stopped (presumably because there was no water going through)... Did I do something wrong? Last season, I ran the polaris and filter at the same time all the time, I think..
The filter had run for 2-3 hours every day while we were gone and the water level didn't change much (no major rains in the last 5 days either), so I don't think (and i really hope) it's not an issue with the normal filter pipes.. so, it must be the pipe that propels the polaris, right? Our polaris has a dedicated booster pump. The pump had a leak in the hose last season, which we temporarily fixed with some duct tape.. I re-taped it this morning and it was fine when we left, so i have a hard time believing all that water was lost through that.. I'll try running it tomorrow with the pool refilled, but would it be possible to lose that much water in 2hrs from a leak in a hose (it basically just sprays some water, not that much water).. it took me 2.5 hrs to refill it with a hose at full force 3 inches, so I'm guessing this isn't the reason.

Can I run the polaris without running the filter to see if that's the culprit? I didn't think that was possible.. is there anything else I can do to pinpoint the issue other than call a pool company?

I'm also wondering if the pool company that closed the pool last season blew out the polaris port correctly and if not, maybe it froze and cracked? Ugh, since I didn't use them to open, I wonder if they would even believe me at this point

Also, no obvious places were covered with water so I think that's all the info I have right now..

Ugh, I'm stressed out..

 

[JasonLion]

From your description, the pump ran pumping water out of the pool fairly quickly until it got below the skimmer and lost prime. I suspect that, with a leak that large, it will be fairly obvious. When you get everything running again, a little looking around should show where the water is being lost. I suspect something fairly obvious, like leaving the valve set to backwash or a complete failure of a pipe or fitting somewhere near the equipment pad.

 

[patplh]

this morning, i turned the filter on and the pressure was 0.. i felt like i could hear water draining from the pool, but wasn't a 100% sure because the drain tube always feels like there is water vibrating through due to how close it is to the filter.. i decided to backwash and rinse a few times since i hadn't done that since i got home ... and there was definitely a lot of DE washed out (seemed to be clean/white).. then i turn it back on and my booster pump line was completely disconnected from the pump (how I didn't notice it visually is baffling)... any ideas why the filter wouldn't pressurize after I filled the pool? it's the priming thing, right? I hope I didn't mess it up with my steps..

now, I'm debating whether to get this fixed, or look into buying a new robot vacuum.. i know this one is around 8 years old.. any thoughts? has vacuum technology advanced a lot? Do I need a booster pump still if I buy a different vacuum? I don't mind investing in a new and better one if this one is going to stop working in a few years.

Thanks,
Patty