Los Angeles Remodel, or Can a regular plumber do a repipe?

[Xizenta]

Hey guys. Long story short, I'm trying to do a remodel to a 28k gallon pool in the San Fernando Valley.

Boy has it been hard finding a quality, affordable contractor. I have found someone affordable for tile and plaster as well as decking. What I'm concerned about is plumbing. As you probably imagined, most of the publicly listed pool contractors are general contractors who don't handle plumbing per se, but want to do the whole job. They can get someone for my job, but they want to add on their own profits. Not to mention, they also do not like the idea of doing partial work and leaving decking, coping, plaster, and tile to the guys I have already found and already trust. I need to find a plumber who can do a repipe, add a water feature, and connect my equipment. I'm having a terrible time of it.

My question is, are regular plumbers generally experienced in the installation of plumbing for pools, typically?

 

[RoyR]

No, need to know pool plumbing...ask the tile / plaster guys, they will know a pool plumber.

What kind of water feature?

 

[Xizenta]

No, need to know pool plumbing...ask the tile / plaster guys, they will know a pool plumber.

What kind of water feature?

I have a big retaining wall behind the long edge of my rectangular pool. It's existing. Thinking of running a return line behind it and just having box scuppers on the wall dump the water back into the pool for aesthetic reasons. Another question about this was a recommendation to have two pumps versus running everything through my variable pump. I have read a little around here about using a "waterfall pump" versus a typical pool pump. All the waterfall pumps I saw on different websites were for ponds. What are the most popular models?

 

[bdavis466]

Look into Pacific Pool Plumbing. They are exactly what you're looking for - plumbing only and incredibly reliable.

https://pacificpoolplumbing.com

 

[Xizenta]

Look into Pacific Pool Plumbing. They are exactly what you're looking for - plumbing only and incredibly reliable.

https://pacificpoolplumbing.com

Thanks, I wrote them an e-mail. Although, they are located like 2 hours away from me on a light traffic day, so I doubt they will be interested.

 

[bdavis466]

They go well into LA so you might have a shot

 

[sktn77a]

A decent plumber knows all about metal, PVC, CPVC pipe (they are standard in most buildings now) and should be able to assemble the plumbing for a pool. You may have to augment any very specific pool requirements. Just be sure you get a good, experienced plumber with references, not some bottom feeder off craigslist.

Post your plumbing layout on here to see if there are any quirks.

 

[Xizenta]

Ok guys thanks. I will also post a diagram before we carry on with the project. I have a question. I have been hearing about "waterfall pumps", "pool pumps", and "spa pumps". I looked around for some waterfall pumps that could deliver anywhere from 100gpm to 125gpm for some water features. I couldn't really find anything. Then I found a "spa pump" that seems to fit the bill based on what I estimate for the feet of head in my application. What's the downside? Is there some reason a spa pump wouldn't work well for a water feature application? I noticed it doesn't have a filter basket in the pump, which I guess would be an issue if I want to run the suction line for the waterfalls directly from the pool and bypassing the filter.

Waterway 3721221-13 Executive Spa Pump

 

[ajw22]

I have seen @mas985 explain about the pump differences.

 

[mas985]

Waterfall pumps are low head and high flow while spa pumps are the opposite. So they would deliver significantly different performance on the same plumbing. With a large waterfall and large pipe, it is possible the spa pump would cavitate.

Can you describe the plumbing and waterfall setup in detail? Pipe sizes, lengths, exit orifice, suction port, etc.

 

[Xizenta]

Waterfall pumps are low head and high flow while spa pumps are the opposite. So they would deliver significantly different performance on the same plumbing. With a large waterfall and large pipe, it is possible the spa pump would cavitate.

Can you describe the plumbing and waterfall setup in detail? Pipe sizes, lengths, exit orifice, suction port, etc.

What I want to do is to put three to five of these bad boys against a wall, about 5 feet above water level Box Scupper Stainless (Custom)

Piping layout not locked down yet but I used a calculator that determined I would have about 40 feet of head coming from my skimmer to the equipment head and out to the features assuming something like 10 elbows and 5 tees. I would probably not run this circuit through my filter or heater. The equipment pad is about halfway through the circuit in length and I would run 2 inch or 2.5 inch suction up to it, with either 3-5 1.5 inch lines coming out at the pump, or a single 2 inch line being shared behind the features in a hydraulically balanced loop with tees reducing to the 1.5" inlet.

I originally assumed like you had said, that the spa pumps have high head and low flow. But if you look at the graph on the Executive 56 by Waterway, they claim to deliver way more GPM than pretty much anything I was able to find in a comparable horsepower rating.

 

[mas985]

Piping layout not locked down yet but I used a calculator that determined I would have about 40 feet of head coming from my skimmer to the equipment head and out to the features assuming something like 10 elbows and 5 tees.

What did you use? Most on the internet are not very accurate. Also, head loss is dependent on flow rate so you can't determine one without the other. And you can't determine either without considering the pump. It is multi-variate problem that needs to be solved as system.

I originally assumed like you had said, that the spa pumps have high head and low flow. But if you look at the graph on the Executive 56 by Waterway, they claim to deliver way more GPM than pretty much anything I was able to find in a comparable horsepower rating.

Only at very low head will they have the high flow rate. But on that side of the head curve, they tend to cavitate. It is not advised to run a pump close to run out.

Also, those scuppers probably don't need a lot of flow rate or it will look more like a fire hose. This says 15 GPM each: Box Scupper — Bobe Water & Fire

So you really only need 75 GPM for all 5.

 

[Xizenta]

Mark,

On the Bobe brochure and website it does say 15 GPM for their box scuppers, but I took that to be for their standard sizes. The standard sizes that they stock and sell are like 2" or 4". These scuppers are like a custom order at 8" wide, so I guess I assumed they would take about twice the 15 GPM advertised on the brochure?

Did you see the flow graph for the Waterway Executive series? I do need to recalculate my head... I don't really have very much confidence that I can predict exactly how many valves and fittings my plumber will use. I just estimated based on what I could see. Is about 40 feet of head typical for a setup like I described? I guess I can provide a diagram later.

 

[WalkerTribe7]

I’m in OC and have an amazing plumber, he’s in our yard right now working on the pool. We also have 4 Bobé scuppers being installed (all custom). I will ask if he goes to the valley. As for the pumps, my husband understands that portion. I believe they are using a variable speed pump on the scuppers. I just wanted to make sure I could control them because 3 are on a raised bond beam and 1 is in the corner at a rounded area. We ended up adding a pump because originally that pump was going to also control the bubblers on the Baja reef but I would have to manually shut things off if i didn’t want it all on together. I don’t even know how many pumps we are up to now! Good luck

 

[mas985]

Did you see the flow graph for the Waterway Executive series? I do need to recalculate my head... I don't really have very much confidence that I can predict exactly how many valves and fittings my plumber will use. I just estimated based on what I could see. Is about 40 feet of head typical for a setup like I described? I guess I can provide a diagram later.

Again, it is not just about pipe lengths and fittings. You also need to take into account the pump that goes on to plumbing and the flow rate through the plumbing. It is not a trivial calculation. If you can put together a drawing I can give you an estimate with that specific pump.

 

[Xizenta]

Again, it is not just about pipe lengths and fittings. You also need to take into account the pump that goes on to plumbing and the flow rate through the plumbing. It is not a trivial calculation. If you can put together a drawing I can give you an estimate with that specific pump.

Here is the layout of the pool. I didn't diagram the plumbing in detail because it hasn't been built yet. I can change pretty much everything except for the locations of the waterfalls and skimmer and vacuum. This is to scale since I drew it over a satellite photo. It was suggested to me that I should put the returns at the shallow side and just go one directional with the flow, as opposed to circular. Anyway, I'm not sure how I want to plumb it. The waterway executive 56 pump definitely seems like it can satisfy the flow requirements and I don't think I could possibly put less than 30 feet of head on it given the distance it's covering? So cavitation shouldn't be a problem?

Any suggestions for how to plumb would be appreciated. I could possibly also put another skimmer in the shallow end to feed the circuit for the water features.

 

[ajw22]

Which way are prevailing winds? Winds affect skimmer placements.

Suction for waterfalls is usually put in a pool wall not a skimmer.

 

[mas985]

If you are planning a separate pump for the scuppers they need their own suction port.

Also, the way the scuppers are plumbed, the first one will get the most flow with progressively less as you move down the line. There are couple of ways around this with either a large header pipe or a binary split which wouldn't work with 5 scuppers.

Also, when I started looking at the pump you suggested, I noticed that it was not a self-priming pump. Most spa pumps are not self priming because they are installed below water level. If you are installing the pump above water level, as is the case with most IG pools, then you will need a self priming pump.

With the information you gave, here are some estimates:

The pump you had chosen on 2.5" pipe would deliver 164 GPM @ 32' of head & use 2513 watts. But again it is not self priming and the water velocity is over 11 feet/sec which probably would not pass inspection.

A Pentair AF-180 Waterfall pump with 3" pipe would deliver 156 GPM @ 14' of head & use 1890 watts.

These results may vary some depending on how the pool is actually plumbed. Also, the spa pump would likely be very loud while the waterfall pump, much less so.

You would have more options if you went with the smaller scuppers and lower flow rate.

 

[Xizenta]

Thanks Mark,

Can you tell me how you did the math?

Also, for the plumbing on the features, I was under the impression that I had two options to balance the output.

1. The plumbers that have seen the job so far recommended running a 1.5" line to each water feature from the equipment pad, with ball valves at the pad to control the flow to each.

2. I saw a picture online that seems to suggest that you can hydraulically balance the output by looping plumbing around from one inlet straight in its center. Can this method be used for 5 outputs over a 30 foot distance or does the concept fail?

 

[mas985]

Can you tell me how you did the math?

It is a bit complicated. Head loss is related to the number/type/size of fittings, pipe length/size, return orifice size, suction port size, other equipment, etc plus the flow rate going through the plumbing (i.e. pump size). But head loss does not equal the equivalent pipe length (common misunderstanding). A simple way of explaining the process is to first determine the plumbing head curve. Plumbing does not have a fixed head loss and it is dependent on the flow rate. The higher the flow rate, the higher the head loss. So if you can determine the plumbing head curve, you can plot that over the pump's head curve and where they intersect is the operating point. So the operating point is dependent not only on the plumbing but the pump you put on the plumbing. This where a lot of web sites fail at head calculations.

Also, for the plumbing on the features, I was under the impression that I had two options to balance the output.

1. The plumbers that have seen the job so far recommended running a 1.5" line to each water feature from the equipment pad, with ball valves at the pad to control the flow to each.

2. I saw a picture online that seems to suggest that you can hydraulically balance the output by looping plumbing around from one inlet straight in its center. Can this method be used for 5 outputs over a 30 foot distance or does the concept fail?

There are actually many options. #1 will work but requires extra plumbing. #2 improves the situation but does not guarantee equal flow rate.

If you want to ensure equal flow rate, go with #1 or use at least 2.5" pipe for the loop in #2. But there are multiple ways of feeding returns. Here is an analysis I did some time ago on the different ways and their performance. Plumbing Loops

In general, as pipe size increases, there is less of a difference between the options. This is because as pipe size increases, the head loss is reduced between the returns which is the cause of the imbalance.