Converting spillover to piped return spa

[Ed J]

I have a gunite pool and a spa. The spa is about 3' above and 10' away from the pool, connected with a spillover and a decorative stream feature. The feature leaks due to 25 seasons of movement (cracks/gaps at pool connection, spa connection, decorative catch basin) so I want to replace it with underground pipes.

Q1) What is this new design called? It'll need some leveling/overflow outlets that connect to pipes that return to the pool.
Q2) What sort of faceplate or connector can be used as an overflow to pipes?
Q3) Do I need a skimmer? Can I get away without one?

While it was leaking, I bypassed the feature with 2 2" PVC pipes and a catch bucket. I'd like the equivalent of that design (though built onto the wall of the spa and not visible).

Any advice? I saw some wide mouth skimmers for vinyl pools that might work if I used a skimmer. Would that work for a gunite pool?

This post: SPA Overflowing in Bypass mode. has a similar design to what I want, but I don't know how the plumbing works from their photo.

Thanks for the help! --ed

 

[ajw22]

Welcome to TFP.

You have an interesting setup. Someone thought they were being very creative in their design without any consideration for long-term maintenance.

I color coded various areas so we can discuss them. It is not clear to me what parts you want to keep.

You could put a few 2" pipes at the level of the spillover and bury them in wall and in ground running into the pool. You need a few pipes to handle the volume of water flow to the pool. It does not need to be a skimmer and can be open pipes.

You could keep the green spillover and let the water fall into the blue basin. Rebuild the basin floor with concrete, plaster, and drains piped into the pool.

What is the white pipe in the basin?

 

[Ed J]

Hi and thanks!

The idiot who designed it would be me. It worked great for 15 years, then cracks developed leading to leaks. In the green area, the spillway, you can see a crack along the middle. That's from years of thermal flexing of the retaining wall under all that flagstone. There is also 2 cracks in the blue basin, one on the vertical wall, one in the base. I believe those were caused by a cracked irrigation pipe that eroded the wall and floor of the basin. The stream itself (the black bucket and white pipe are on it) has a 1/4" gap now between the pool and the stream, again caused by years of season flex. I patched it several times.

I don't want to keep any of it. The fountain turns into a flower bed. The stream gets removed. The green overflow either gets filled in and replaced with some other overflow/leveling outlet, or gets cut and somehow tied into a drain of some sort tied to the 2x 2" pipes.

> You could put a few 2" pipes at the level of the spillover and bury them in wall and in ground running into the pool. You need a few pipes to handle the volume of water flow to the pool. It does not need to be a skimmer and can be open pipes.

Yes! How do you think that would look from the inside of the spa? As 2 round PVC pipes flush with the tile, no grate? Or is there some sort of fixture or plate that would attach to the pipes? Any suggestions there? Like this? (attached) Or this? (attached)
Do you think instead of an overflow at the intended water line, it could be a lower level grate with a reverse u-bend that sets the waterline? Is that a thing? See "is this a dumb idea" picture.

The white pipe in the basin is connected to a fountain pump that let us make the stream flow when the pool/spa wasn't running. I'll seal that and disable the pump.

 

[Ed J]

I take it back, that would be a dumb idea, it would generate an air gap.

An alternative would be to have a skimmer-type bucket that had inlet and outlets and a cover, not sealed to expose the airgap.

 

[ajw22]

Your dumb idea will siphon the spa down to the pool water level once the water gets flowing.

What model filter pump do you have? You need large enough piping to handle the GPM flow from your pump or the water will backup and overflow the spa. If you have a VS pump, you can adjust the spillover flow rate.

I think an open round pipe in the wall would work. You can also put a grate over it, but the grate needs to allow enough flow.

I might look at using a horizontal main drain on the wall at the spillover level.

You are going to do very invasive surgery on the spillover wall down into the ground.

 

[ajw22]

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[Ed J]

I have 3 pumps.
1) The main/pool/spa pump with diverters is an AO Smith K48J2PA105C1m 1/2 HP. This was a replacement when the original failed, which was a larger pump I think. There is a "top off" valve attached to the outlet that keep the spa filled, which is about 20% open.
2) The "spa jets' pump which drive the top circle of jets is an Emerson 1081, EAQ1152, 1.5 HP.
3) The fountain pump, not run since the stream started leaking, an AO Smith 3/4 HP K48K2PA101A1.

I believe the spa jets are a closed circuit and don't contribute to the overflow. Maybe I'm wrong.

In pool mode, the top off valve keeps the spa decoratively overflowing and mixes the chemicals (main pump)
In spa mode, it's a closed circuit, no overflow. Spa mode uses the main pool pump.

I built a catch basin and pipes to bypass the stream (see original pics) with 2x 2" pipes, and that worked without overflowing, so I think 2x 2" is OK to handle the 20% top off.

I think an open round pipe would work as well, not sure if that's attractive. I agree it would need to provide the right flow.

For a a horizontal drain, are you suggesting mounting it vertically in the wall, or in some horizontal spillway manner?

Yes, this is very invasive, will need to pierce the gunite of both the pool and the spa to install the pathway. I'm replasting, so this is part of that work. I just want to get the fixtures right.

Thanks! --ed

 

[ajw22]

For a a horizontal drain, are you suggesting mounting it vertically in the wall, or in some horizontal spillway manner?

See post #6.

Horizontal at the spillway level as it sets the maximum water level for the spa. Any water level over that point will flow into the pool.

 

[mknauss]

Any floating debris in the spa will have no where to go.

 

[Ed J]

> Any floating debris in the spa will have no where to go

Yah, I agree, which is why I was wondering if a skimmer+bucket was needed. If the pipes were open 2" circles, then they could get clogged, otherwise it'll go into the pool, stuck in the pipe, or stick in the cover in the pool, if there is one.

> Horizontal at the spillway level

Gotcha, so it would need some kind of dam around it, yah? maybe something as low as 1" backing the drain?

All my questions are to arm myself with the contractor to make sure we make something that has a chance of working. Thanks again for all the support.

 

[ajw22]

> Horizontal at the spillway level

Gotcha, so it would need some kind of dam around it, yah? maybe something as low as 1" backing the drain?

I am not sure what you are thinking. A diagram may help.

I was thinking you would fill in the spillover notch during the renovation and insert the pipes or drain in the area.

You could put a skimmer in that place. But a skimmer has a small output pipe in the bottom. A skimmer is designed for pump suction. I don’t know how well it will naturally drain into the pool. And the skimmer can easily clog with debris without pump suction.

I think you will need to hand skim surface debris from the spa. It will not naturally carry anything big into the pool.

 

[Ed J]

Agree.

So cut the concrete and flagstone in the dark blue area, put in a horizontal channel drain. Run the 2 2" pipes (light blue) from the drain to the right, under the retaining wall, then to the pool along the path of the stream. Add some sort of small backstop wall (red) to enclose the overflow area. Like the 2 guide walls that already exist to guide the water over the edge. Let's call this proposal #1.

Proposal #2, which I don't like, from the contractor, is to bore 2 new holes for 2" pipes at the waterline, with or without some sort of grate or something more than just a hole. Then run those 2 pipes to the pool. The existing overflow slot (yellow) would be filled in and tiled over. In my original post, I asked Q2 what was what sort of grate might work for the new outlet, some sort of vertical drain grate? It would of course be easily blocked by floating leaves, probably similar to proposal #1.

Proposal #3 would be to install a regular pool skimmer (or wide mouth spa skimmer) in either area, with bucket and pipes leading down, though drained only by gravity, not the usual suction.

OK, thanks again for the help and ideas. I'll discuss with the contractor. --ed

 

[ajw22]

I was going to put the horizontal drain in the spillway notch instead of the blue pipes.

 

[Ed J]

Ah. Yes, that would be ideal, but finding a part that fits is hard. All of the horizontal drains I've found are 36", part of the pool code to keep them wide enough to not suck people in, and the existing notch is 18x3". However, since they are likely to construct any new notch out of concrete they way the spa was originally constructed, I'm guessing that just putting pipes in the current spillway and cementing them in would work. See pic. Yellow is the current spillway. Add red pipes and cement them in (black). This would be a good simple solution. Thanks!

It also occurred to me that maybe what the contractor intended to build was like so (see pic 2): Pipes are added through the side of the spa below the water line, and exit into a "sump pit" bucket below the water line. An exit pipe set to match the desired water line in the spa connects to the pool. The sump pit would have a cover like a skimmer so it could be cleaned. This is also pretty simple.

--ed

 

[ajw22]

Your sump pit design depends on water flowing up and a siphoning effect. There can be conditions when the spa is drained and the pipe loses its prime. I think it will be unreliable and a PITA.