That massive pool restoration project

Some of you will remember this pool from the old forum. It's a VERY large residential pool built at least 50 years ago. 77' X 27' and ranging from 3 and 1/2 to 11 feet deep. Best calc for volume is 85,000+- gallons. Dave S. and Kelly, you've gotten me to where I am right now on this project.

Todays dilemma is reducing the 2.5 inch return line to match return fittings through the shell. It seems most available eyeball type fittings are 1.5 inch f.i.p. The plan is to return about 125 gpm through 3 or 4 through the shell outlets. I've obtained a 2" fip fitting that has 1.5 threads inside it. That has a nice wide escutchen that would cover the giant hole I'll be core drilling through the 18" shell. Believe it or not, the pool seems to have been built entirely of fieldstone and then hand troweled concrete applied to the interior. It's really tough concrete and my guess is the drilling will be a heck of a struggle. I cut the skimmers relatively easily with an angle grinder and concrete blades. The question is whether the 2" is overkill. To get the 2" through the shell will require a 3" core bit, but 1.5 only a 2.375" bit. Since the return water is forced through 1" eyeballs anyway, would reducing the 2.5 inch return line to 1.5 inch shell penetrations make any difference in THD? I'm renting tools tomorrow. Please give me your thoughts.

Regards,

Josh

Hi, Josh,

Glad you posted back. Fascinating project. Post a pic or two when you can.

I THINK I understand your issue. Short answer...I would reduce to 1.5 outside the wall and penetrate the wall with 1.5".

That said I would consider no less than 4 return eyeballs to get close to that 125gpm.......5 would be even better if possible. Keep in mind, I am guessing based on my pool. I've got 3 returns, pumping 100gpm, and I wish I had 4. "mass985" posts here frequently and he has a good grip on THD. I'm sure he'll see this and/or you could PM him.

Food for thought....I just core drilled 4 - 3" holes through 3.5" of concrete with a milwaukee 1/2" drill and it was an unbelievable task. You're taking on a far greater challenge. There are folks who have $10,000 portable core drilling equipment that would do that job for you if you chose. I'd at least call for a price.........they're in the yellow pages if you're not too far in the country. (notice I didn't take my own advice....I was too cheap :D )

Kelly has been absent since the forum came back up. He's in his busy season, for sure.

If I may put my 2 cents in......

Reducing to 1-1/2' through the wall is fine. Considering the GPM and the size of the pool, 6 inlets are probably best.

Thanks Dave and Zina. New information based on yesterdays core drilling. Only the 3 inch bit was long enough to work and the drilling was unbelievabley tough. We rented a huge Hilti rotohammer and the short version is on 3 holes. The concrete was easy, but then another 16 inches of granite or quartz made it each hole a 2 hour battle for 3 of us. Summary: Looks like I'm now looking for a much different return fitting, Clearly the three 2.5 inch lines through the shell will deliver the volume of 125 gpm that's the target. Has anyone seen any fittings for 2.5? Check out the photos from the day before. I'll post new ones soon.


Josh

Happy New Year one and all. I've revitalized this thread to help familiarize all with this wild pool. Last year was a huge advance in the very very long history of this pool. Summary of progress: Complete filtration system installed and it worked fabulously. I installed the intelliflo 4 X 160 and ran it at about 50% rpm capacity for 10 hours per day. CRYSTAL clear with BBB method and I also bought a dolphin HD which is really a wonderful version of robotic cleaners for the 77 footer.

Now for this years fundamental question: Something here is slowly leaking and has done so for years. I just cannot find it. Not the new plumbing. Not the skimmers. Not surface cracks. Maybe the original and massive main drain valve. It's at least 12 feet below grade and frankly, not repairable without a world class excavation that might be a disaster anyway. If I simply assume I need to add water as I've done from a hose in the past, can I find a better and less risky water source than my well water?

I'm thinking of adding an above ground 1.5 hp and 18" sand filter which can be had for about $260 on ebay and drawing water from a stream that passes within 15 feet of my main filter setup. Could I tee into the 2" that runs from my main pump but before the TR140 with filtered stream water? The main returns are 2.5" but the pre filter side is 2" Yes, some algae would enter the system, but proportionally very small amounts. I use liquid chlorine at 12% and have no problem keeping clear water.

I know this is extremely unconventional, but this pool requires some thinking outside of the box. Frankly, we've got maybe a 90 day season, so the expeditious solution may be more sensible than the costly repair.

Regards,

Josh

If you insist on using the stream water then I would add the chlorine to that water and let it mix in some kind of holding tank before being discharged into the pool. I'm not that concerned with the algea but am concerned with the introduction of harmful bacteria.

Been using stream water for probably 6-7 years and no problem. I do run the chlorine up some after topping off but not to shock levels. Heck, people swim in ponds all the time. I use a small sump pump if I'm not in a hurry to fill, and run it into the skimmer with the pool pump running. This takes care of any dirt or stuff that may get sucked up. If I need a rapid fill, such as when I was chasing a 50 GPH leak, I used an old 1 HP pool pump. Then I pumped into the waste line, set the regular pool sand filter to backwash, and the filtered stream water came out the skimmer thus passing it thru the pool filter in the right direction. Obviously this assumes the stream is relatively clean and there isn't a chicken farm or something like that upstream.
Go for it.
Al

Thanks Mark and Al!


My stream is mighty clean and is the source I fill from every year (after the acid wash down and 6 gallons of fresh acylic blue heaven on the bottom only) in Mid May with a 150 gpm trash pump. I can run the water directly into a 1" trichlor puck feeder, but I try to keep CA at 40 ish. The core of the question is really whether the tee idea will work. I want to keep flow rates up to 90gph and run the intelliflo to that level. Does anyone think I'll need a backflow preventer on the main pump side? Any hydraulically inclined minds care to weigh in?

P.S. Some of you thinking about new pumps might seriously want to consider this intelliflo. By throttling down to bare minimum turns per day and keeping ahead of the water, I added only about $50 per month to my power bill. Considering 85K gallons, I think this pump may pay for itself VERY rapidly. Just food for thought.

Regards,

Josh

I assume you wouldn't be running both the pool and stream pumps simultaneously. Rather than installing check valves I would just use ball valves and manually throw them when needed. Check valves do present some added flow resistance. PVC ball valves are also cheaper and you don't have to worry about any spring mechanism being affected by the chlorine.
Al