POOL/SPA with spillway number of returns in each?

[STANJP]

I am building a POOL/SPA combo connected with a spillway. I will be using a Hayward VSR TriStar 900 1.85 Hp pump and the pool is approximately 14,000 gallons and the spa is 900/1,000 gallons. There are a lot of articles about the number of skimmers and returns but I have not been able to find any articles on how to divide the returns between the pool and spa. For the size of my project, I understand that 2 - 4 returns for the system are what is ideal. In normal operation it makes complete sense but when in SPA mode it makes me stat having question. The main concern is having enough returns in the SPA when 100% of the circulation is for the spa in SPA mode. I do not want to create resistance on the pump having to pull and return the water to the spa through too little returns. This would also slow down the heat up time.

I would like help with how many returns to place in the SPA and how many returns to place in the POOL?

I do not want to create stress on the pump/filter/heater system by having too little returns in the SPA when in SPA mode.

I don not want to have too many returns in the POOL/SPA together when in normal operation. This would eliminate my velocity and hinder circulation.

How do I sold my problem when both are operating in normal filtration mode and when I am using only the SPA?

Best,

 

[HermanTX]

Hi and welcome to TFP.
One key component will be the size of your suction and return lines. As a minimum you want 2" suction and 1 1/2" return lines. Some go with 2 1/2" suction.
I have similar size pool and have 5 returns - (all 1 1/2" size). I have 2" suction lines. A typical set up could be 2 skimmers (independently run back to the equipment pad), a main drain and 4 returns. Some areas do not use main drains.

When in SPA mode, you will have a drain in the spa which will be 2" suction (for example) and your return may be 2" or 1 1/2" dependent on your number of jets and type of jets. Some people put special jets which may require different size plumbing. Most have 5 or 6 returns to the spa. So when in SPA mode, you have suction from the spa drain through the pump and back to the spa jets. There is no flow to the pool when in SPA mode.

When in POOL mode, with a spillover, you have suction from your skimmers and/or main drain, through the pump and back to your pool plus you will have 1 additional return to the spa. (this return is closed off when in SPA mode). This puts majority of your return flow back to the pool with the exception of the one return to the spa that creates the spillover.

It is best if your can put plumbing in to control your spillover return. I have similar set up but my return to the spa for the spillover cannot be controlled - meaning when in pool mode there is always flow going to my spa as well and creating the spillover effect. If you can plumb it with a bypass and valve to the spillover return line then you have better control of that flow to the spa when in Pool mode. However, the spillover return would not be used when in Spa Mode.

I am asking @ajw22 to comment on piping if he has any additional thoughts.

 

[ajw22]

First of all for your pool I feel the minimum is two skimmers and 3 returns.

For your spa there are two ways spas are setup:

1. One or two spa returns connected to your main pump, filter and heater and a seperate suction, and pump, flowing water directly to spa jets. Depending on the size of your spa you can have 4 to 8 jets or more.
2. The other way is to connect all your spa returns and jets to the main pump, filter and heater.

You can get more water pressure and flow out of the spa jets with a dedicated pump. larger pipes, and no restrictions from the heater and filter. You also have more flexibility in how you use the spa with relaxing calm water from your main pump or can turn on the jets when you want the water therapy.

The second way using one pump is the simple low budget way to go.

Your worries about creating resistance for the pump and stress on the system are unfounded. The pool pump and system can handle whatever number of returns you decide you want. THe heater will heat up the pool or spa at the same rate regardless of the number or size of your returns.

Figure out how many pool returns, spa returns and spa jets you want and that dictates if 1 1/5', 2" or 2 1/2" or 3" pipes are needed. The Tristar 900 pump can handle whatever.