Fixing a pool on Shabbos

This past Shabbos an interesting shailah came up in our bungalow colony. Apparently there was a leak in the pool and the owner of the colony had asked the pool repairman to come on Sunday and fix the pool. Well, instead of coming on Sunday, he decided to come on Shabbos. The only reason we knew about it was because after he fixed the pool he turned on the water to refill the pool. In this particular colony our water pressure is so great that when you fill up the pool noone has water in the bungalow. When we saw that we had very little water in the bungalow we checked the pool and sure enough it was being filled up. A little investigation revealed that some kids had seen the repairman come in and fix the pool. The shailah that I raised was could one use the pool after Shabbos being that it was fixed on Shabbos.

The halacha is that you can give work to a non-jew to do on Erev Shabbos as long as you don't need him to do the work on Shabbos. For example, you can bring clothes to the cleaners right before Shabbos since you don't need it until Monday and he could do the work on Sunday. However, the Rema paskens that if you know the non-jew did the work on Shabbos then l'chatchilah you can't get benefit until k'dei sh'ya'su. The Biur Halacha points out that this is only for issurei d'oriesa but for an issur d'rabanan you can get benefit right after Shabbos.

In our case of the pool, I think there are two issues here. The first is the actual repair of the pool which could involve an issur d'oreisa (depending on what was done). The second issue is filling up the pool which in my opinion should be an issur hachana. However, I think hachana is only a d'rabanan. (Please correct me if I'm wrong). Now, the actual repair took no more than 1 hour so for that you would only have to wait an extra hour after Shabbos intil the pool is used. (and since noone was going swimming until the next day it wasn't a problem). Regarding the hachana issue, since it is only a d'rabanan you would not need to wait at all and you could use the pool right away.

I was also wondering that maybe there is even a better heter. You can't get hana'ah from a melacha a non-jew does for you on Shabbos. But maybe swimming in the pool is not called getting hana'ah from the melacha. The melacha was fixing the pool. Maybe swimming in the pool is an indirect hana'ah and not tied to teh melacha at all. Especially in this case the pool had a leak the last few weeks and was usuable even with the leak. The owner just decided to fix it now for some reason.

Finally, a second question that I had was a general question of how to define k'dei she ya'asu. Let's assume filling up the pool was d'oreisa and one needed to wait k'dei she ya'asu even on filling up the pool. When do you wait? It takes around 24 hours to fill a pool and the first 9 hours of the filling was done on Shabbos. For example, the pool was filled from 1 pm Shabbos afternoon thru 1 pm Sunday. Do you have to wait an additional 9 hours after the entire pool was filled (from 1 pm Sunday until 10 pm Sunday) or just wait 9 hours after Shabbos (9:30 pm motzei Shabbos until 6:30 AM Sunday morning) even though the pool was still filling up.