Good morning everyone. I’m hoping a few minds might assist me with some issues I’m having with a new pool build, specifically regarding a negative edge that spills into a catch basin. It’s a freeform pool that is approximately 865 sqft that ranges in depth 3.5 ft to 8 ft. It has an elevated spa with 8 jets and 2 drains and 1 return that spills over to the main pool with 2 skimmers, 2 floor main drains (and I believe 2 side wall drains?) with 10 returns and 3 waterfeature waterfalls. The main pool has a spillover to a catch basin located in a sunk fire pit adjacent to the pool that includes 2 drains, an autofill jet and overflow drain located at the top that empties into a sump pump pit that drains to the back yard. Plumbing includes schedule 40 pvc solvent welded and Pentair 2” x 2.5” neverlube valves. There are separate lines for the skimmers and main drains. Right now, the main pool and spa are powered by a Pentair Intelliflo VSF, and the waterfeatures by a Pentair SuperFlo VST. Other equipment includes a Pentair 520 sqft filter, Pentair master temp 400k propane heater converted for natural gas, a jandy spa blower and Pentair booster pump for cleaning.
Now to the issue. Originally the catch basin drains were connected to the main pool pump. We were having issues with basin overflow happening (overflow getting pumped into the back yard) when the pool pump was on that was exacerbated by using the water features. The PB said it was likely due to the drains not having enough suction in the catch basin to keep up with the water flow coming over the spillover so he switched the basin drains to the water feature pump. This didn’t make sense to me as when the pool pump is on, its sending water over the spillover, but the basin drains wouldn’t function when the waterfeatures are not on. But he insisted and we tried it but sure enough, when both the pool pump and waterfeature pumps are on, the water feature pump is so strong it empties the basin before the spillover can make up the volume and shuts the motor off. With the waterfeature pump off and the pool pump still on, now the autofill and spillover volumes kick in and rise the basin levels quickly to the overflow again kicking water into my back yard. I pointed all of this out to the PB and he is going to work with the plumber to try and come up with a solution.
After reading a bit on this forum, I believe there are a couple of things at play here. The first and probably most important is I believe the catch basin is too small. The second is I understand the basin should probably have its own pump and electronic Water Leveling Monitor. Does this sound right? What do you think the mitigating strategy options are? The most challenging will be to change the basin size, are their other options if I have to live with the current basin size? Many thanks for reading and putting your collective minds together, much appreciated!
Rough dimensions of the catch basin:
21” W, 92” L, 43” H (to the overflow) = 48.0764 ft³ ~359 gallons
The spillover length is approximately 92” long
Now to the issue. Originally the catch basin drains were connected to the main pool pump. We were having issues with basin overflow happening (overflow getting pumped into the back yard) when the pool pump was on that was exacerbated by using the water features. The PB said it was likely due to the drains not having enough suction in the catch basin to keep up with the water flow coming over the spillover so he switched the basin drains to the water feature pump. This didn’t make sense to me as when the pool pump is on, its sending water over the spillover, but the basin drains wouldn’t function when the waterfeatures are not on. But he insisted and we tried it but sure enough, when both the pool pump and waterfeature pumps are on, the water feature pump is so strong it empties the basin before the spillover can make up the volume and shuts the motor off. With the waterfeature pump off and the pool pump still on, now the autofill and spillover volumes kick in and rise the basin levels quickly to the overflow again kicking water into my back yard. I pointed all of this out to the PB and he is going to work with the plumber to try and come up with a solution.
After reading a bit on this forum, I believe there are a couple of things at play here. The first and probably most important is I believe the catch basin is too small. The second is I understand the basin should probably have its own pump and electronic Water Leveling Monitor. Does this sound right? What do you think the mitigating strategy options are? The most challenging will be to change the basin size, are their other options if I have to live with the current basin size? Many thanks for reading and putting your collective minds together, much appreciated!
Rough dimensions of the catch basin:
21” W, 92” L, 43” H (to the overflow) = 48.0764 ft³ ~359 gallons
The spillover length is approximately 92” long
