Need help diagnosing poor water flow

[bignick]

I need help and advice regarding my sister-in-law's in-ground pool. Compared to my dinky pool with no diverter valves, this pool is a lot more complicated (19,000 gal with spa, built in the 70's, 2 skimmers and 2 floor drains). The pool was inoperative for many years and was a green swamp with inches of plant debris so I had the pool emptied and pressure washed last year. There doesn't seem to be the amount of water flow as I see in my pool and the pump sometimes has difficulty priming; the pump basket area is never completely full of water. A couple weeks ago, the incoming water slowed to the point the filter had barely any pressure. I thought it was a clogged skimmer line, so I snaked the skimmers for 15ft and didn't find anything. I called a guy and he noticed one of the diverter valves was leaking. He replaced the o-rings in all three valves pictured below and it did help because the DE filter can now build up about 16psi.

In the pic below, the upper right inset shows the current valve settings. The tech has it set so it's only pulling water from one of the skimmers. He's saying that although he replaced the o-rings there is still a suction side leak and he's suggesting that all 3 valves need to be replaced in order to have all 4 inlets pulling water. He did show me that at least one of the screws on a valve top is stripped and you can pull it out with your fingers. There is also a stream of small bubbles from the 2 pool outlets.

Does this sound like a plausible solution to the circulation issues? I hesitate because he's offering to replace all three valves, replace the DE filter with a cartridge filter, and remove all of the unused gas and solar equipment and piping for $2100. Valve replacement alone was $600-700; is that cost reasonable?

Also, is it common to separate the two skimmers lines, but have the main drains on a single line?

Thanks for any assistance and advice you can offer.

 

[mas985]

Can't comment on the quotes but to troubleshoot a little, what happens when you put the valves into spa mode (i.e. close off skimmers with valve right before pump)? What is the filter pressure and does the pump prime completely?

Also, is it common to separate the two skimmers lines, but have the main drains on a single line?

Yes, that is common and proper way to plumb those features. The main drain is actually a pair of drains connected together with one line back to the pump. This is done to prevent entrapment.

 

[Cwiggs]

From what I've seen you can buy a diverter on Amazon for around $50, and the PVC, glue and couplings are cheap, so all in all, I assume you'll be under well $300 for parts. Not 100% sure if it's possible but I've heard people using general handymen to install SWCG, and installing valves is easier than a SWCG. I wonder if you could buy all the diverter valves, PVC, etc and just pay a handyman to install it all? Provided you give him a diagram/drawing of what the end result should look like? Just a thought.

I also wanted to mention your setup sounds pretty similar to mine. I have 4 pipes on the suction side, 2 skimmers, 1 main drain (2 drains on the bottom of the pool), and a vacuum port. When I first got the pool (with house purchase) I had issues with the vacuum not getting enough suction. A friend of mine who owns a pool business told me to just run with 1 skimmer, no main drain, and vacuum port open, which "fixed" the issue. With that setup my suction side vacuum works great, and debris in the pool isn't an issue. I do have a VS pump, which I don't run at 100%, which contributes to the lack of pressure. At the end of the day, it isn't ideal but it "works" for now. I don't have any bubbles in the returns so I don't think I have a leak, just low pressure for some reason?

Sounds like your issue is worse than mine as I've never had the pump not prime, and the PSI on the filter has always been fine.

Good luck on troubleshooting though, TFP has a lot of smart minds that can help.

 

[bignick]

Can't comment on the quotes but to troubleshoot a little, what happens when you put the valves into spa mode (i.e. close off skimmers with valve right before pump)? What is the filter pressure and does the pump prime completely?

Yes, that is common and proper way to plumb those features. The main drain is actually a pair of drains connected together with one line back to the pump. This is done to prevent entrapment.

Thanks for your input. I'll have to manipulate the valves when I'm over there on Friday. To be honest, I never made sense of the valves until I was composing my message and studying the pic. Now it's pretty clear to me. Both floor drains on a single line makes sense too.

From what I've seen you can buy a diverter on Amazon for around $50, and the PVC, glue and couplings are cheap, so all in all, I assume you'll be under well $300 for parts. Not 100% sure if it's possible but I've heard people using general handymen to install SWCG, and installing valves is easier than a SWCG. I wonder if you could buy all the diverter valves, PVC, etc and just pay a handyman to install it all? Provided you give him a diagram/drawing of what the end result should look like? Just a thought.

I also wanted to mention your setup sounds pretty similar to mine. I have 4 pipes on the suction side, 2 skimmers, 1 main drain (2 drains on the bottom of the pool), and a vacuum port. When I first got the pool (with house purchase) I had issues with the vacuum not getting enough suction. A friend of mine who owns a pool business told me to just run with 1 skimmer, no main drain, and vacuum port open, which "fixed" the issue. With that setup my suction side vacuum works great, and debris in the pool isn't an issue. I do have a VS pump, which I don't run at 100%, which contributes to the lack of pressure. At the end of the day, it isn't ideal but it "works" for now. I don't have any bubbles in the returns so I don't think I have a leak, just low pressure for some reason?

Thanks for your reply. I was watching a video from Inyo Pools on how to diagnose leaking valves, so I'll have to test to see how bad it is. I thought about trying to replace the valves myself because it's similar to replacing an irrigation valve, but the section from the valves to the pump looks complicated. I'll have to get a couple more quotes from other techs.

Now that I've researched a little more, maybe 16psi is not too bad and maybe I don't need to pull from the floor drains similar to yourself.

 

[Cwiggs]

Now that I've researched a little more, maybe 16psi is not too bad and maybe I don't need to pull from the floor drains similar to yourself.

16psi is around where my pressure is at on the filter as well. I'm not sure what the downsides of not pulling from the floor really is, I'd love to hear what other people on here say. However I've been doing it for about 9 months with no foreseen issues.

 

[bignick]

Can't comment on the quotes but to troubleshoot a little, what happens when you put the valves into spa mode (i.e. close off skimmers with valve right before pump)? What is the filter pressure and does the pump prime completely?

I closed off the skimmers so it was just pulling from just the spa and the filter still showed 16psi with the same water level in the pump basket (about 75% full). The water level in the spa did drop about 5" but I think that's because the water level was low and there was little spillover from the pool. The water level came back up when I reset the valves.

There was something else strange but I don't if it's anything. When I switched from the shallow end skimmer to the deep end, the flow went way down, then a surge, then down, then finally back to a 75% full pump basket. Air bubble? I switched shallow-deep again and it didn't happen again, although I never turned off the pump in-between.

I did the soap suds trick against the valves and didn't see it drawing in any suds, but it was hard for me to notice. One thing I didn't notice before is that when I turned off the pump, water squirted out of the valve with the stripped screw, so obviously that's a main failure point. I'm assuming that I can't just replace one valve because of the proximity to the other valves, but before I replace them, I'm going to try stuffing the stripped screw hole with toothpicks to see if it will catch. Might be a stop-gap solution, but curious on the results. I'll also replace the pump lid gasket just to eliminate that as a source of air.