My IG pool has been leaking for a long time. For various reasons, I have just been putting more water in it. Now I am determined to fix it.

Various experiments and observations over time have lead me to the conclusion that there is a leak in the pressurized pipe used for used by the Polaris. I filled the pool and did not run the main pump or the Polaris pump for 4-5 days and the water level stayed constant. Turned the pump back on and the water level dropped. Another indicator is that the Polaris is extremely lethargic, suggesting that it may not be getting enough water to make it move at normal speed.

I had a pool repair guy out doing some work on my pump and he looked for possible openings around the skimmer and caulked a couple of places. It didn't help.

One of the mysteries is that I'm not seeing any water coming up from under the pool deck. All that water has to be going someplace!

Another discouragement is that the Polaris supply pipe in question is under the pebbled/concrete pool deck and I've not been able to identify a spot where I should start tearing things up.

Question: Give the above information, how confident would you be that it's the Polaris supply pipe?
Do I need a leak detection service?

Having battled algae all summer and this leak for a long time, I'm starting to calculate how many cubic yards of dirty I'd need to make the pool into a flower garden.