Can't wrap my head around new spa plumbing

[BorderlineCreep]

I'm going to be adding on a spillover spa to my existing pool and I'll be doing it myself. I'm not totally incompetent, I'm a state certified building contractor so I have the skills to execute this 'somewhat' flawlessly. I've got the structure and finishes all figured out, however the plumbing has got me a bit confused. Mostly it's the flow rates of different sized piping, how to calculate for loss of downsizing fittings and the appropriate sizing to achieve what I'm trying to do. I've got a fairly detailed drawing, but nothing is really set in stone. I'm hoping some of you professionals or keyboard pros might have some better insight for me. A second set of eyes for big projects is always a good idea. There are notes on the drawing with some more pertinent information, but am happy to discuss it in more detail. Thanks in advance.

 

[ajw22]

Welcome to TFP.

It looks like you are missing drains in the spa floor for the filter pump heated water. You show what you label as "pool return/spillover supply" but have no suction for that water flow when in spa mode.

Your plumbing with two pumps for the spa should be...

How many spa jets will you have?

See Equipment Pad Best Practices - Further Reading for guidelines on plumbing flow rates.

Also see Gunite Spas - Further Reading

Will you have an air blower or venturi air line plumbed into the spa jets?

This is the way my spa is setup with two pumps...

See the discussion about spa plumbing in...

New pool build in LV

Hi, First I am super thankful for all the great help I got from this forum in the past! :) I’m in the process of building a pool and added quite a few water features: 1x 6’ sheer (12.5’ radius) 3x 1’ rain sheer 6x deck jets 1x bubbler Now I am trying to figure what kind of pump I will need...

www.troublefreepool.com

 

[BorderlineCreep]

"It looks like you are missing drains in the spa floor for the filter pump heated water. You show what you label as "pool return/spillover supply" but have no suction for that water flow when in spa mode."

"How many spa jets will you have?"

"Will you have an air blower or venturi air line plumbed into the spa jets?"

Hi! Thanks for the quick reply.

It occurred to me after I went to bed last night that I probably should have included my understanding of the plumbing layout as I see it now, though absolutely subject to change. I'll answer these questions and include a drawing of the existing layout, as well as my idea of the new plumbing so far. It is drawn for the sake of clarity, final product will be much more elegant.



"It looks like you are missing drains in the spa floor for the filter pump heated water. You show what you label as "pool return/spillover supply" but have no suction for that water flow when in spa mode."

I intended the spa floor drains to only function in recirculation of heated (or maybe even cooled) spa water. Intake from the pool through the filter and chlorinator and returned to the spa should replace all the water in the spa at least 1x every 60-90 minutes. Supply for those in spa mode can be seen in the drawing below.

"How many spa jets will you have?"

I figured 8-10. I'm flexible with the number of jets based on the available flow of water.

"Will you have an air blower or venturi air line plumbed into the spa jets?"

I can, however I really care less about bubbles or massaging action and more about the pressurized hot water. I figured a blower would be a good option so I could turn them on at my convenience.

 

[ajw22]

Your plumbing design is non-standard. No off the shelf automation system from Pentair, Hayward, or Jandy will work with your plumbing design.

What model is the spa heater?

You need a filter between the spa pump and spa heater.

8-10 spa jets plus 4 spa returns says you are dividing the spa pump flow by 12 to 14. If you spa pump can flow a maximum of 100 GPM you will get maybe 8 GPM out of each jet or return. That would only give a good jet feel with a 1/4" orifice in the spa jets.

Consider using a more standard pool/spa plumbing setup.