It is better to have one pump of 4.2 hp or 2 pumps of 3hp each

[Patterson]

Two pumps of 3hp vs on pump of 4.2hp.

We are looking into buying a spa and need to decide wwther better to have 2 pumps of 3hp or one pump with 4.3 hp. Would like to have medium type hydrotherapy

It is a 2mtx 2 mt spa 

good insulation

UV filtration and Ozone 

Water diverder

15/26 AMP

Standard Heater Size 3KW Circulation Pump Smart Filtration (Circ Pump x1) Pump

Smart Flow (1 x 4.2HP One Speed Massage Pump)

Information on Jets -Air Injector Jet 20 Hurricane Directional Jet 2 Hurricane Spin Jet 2 Hurricane Pulsating Jet 2 Hurricane Message Jet 0 Mini Hurricane Directional Jet 9 Mini Hurricane Pulsating Jet 1 Mini Hurricane Spin Jet 6 Duo DirectionalJet 15 Duo Pulsating Jet 6 Super Jet 0 Ozone Jet 1 Laminar Waterfall Jet 2 Total Number of Jets 66

We are 2 of us and occassionally kids may come

 

 

 

 

 

[CanadianSpaTech]

Using a smaller circulation pump (depending on the pump used) will be more cost effective then running a larger main pump on low speed for heating and filtering. When they tell you hp rating those numbers are subjective and can be fudged by the MFG to make it seem more powerful to the consumer. The best way to tell the hp rating of a pump it is always best to know the amp draw in high speed of a 2 speed pump. 8 amp 2 hp, 10 amp 3 hp, 12 amp 4 hp. For heating and filtering look for the low speed amp draw. A large main pump might have a low speed amp draw of say 3 amp but circ pumps can range from .8 amp up to 5 amps depending on the circ pump. If you live in a cold climate you want to make sure the electrical hook up can handle running both the heater and the main pump on high speed at the same time so you can heat while you enjoy the spa. Some systems you can run the heater and the main pump at the same time on low speed but once you put the main pump into high speed the heater cuts out if the GFCI breaker is not sufficient to handle the total amp draw of everything running at once. If there is sufficient amps at the breaker most control systems can be made to run everything at once by making a change to a dip switch on the circuit board. 

[ratchett]

On 2/27/2023 at 3:13 AM, Patterson said:

and need to decide wwther better to have 2 pumps of 3hp or one pump with 4.3 hp. Would like to have medium type hydrotherapy

As CanadianSpaTech mentioned - Jet pump horsepower numbers can be heavily inflated when testing on the bench - basically they test at a higher voltage to force the motor to run at a higher horsepower (which would kill the jet pump very fast, but doesn't matter for a 2 minute test).  Back in my car stereo days we called that the "ILS Standard" for car amplifiers - because the only way you'd hit the advertised wattage is "If Lightning Strikes" 😄

As CST said - pump amperage is a much more useful number, and of course this never really mentioned in the marketing/advertising.   The only way to know for certain is to pull the front access panel and read the specs on the pump motor itself.

Also know that plumbing designs play a role in jet pressure - hard 90-degree bends in plumbing cause cavitation which decreases flow pressure.  Some brands use angled and curved plumbing to ensure no hard bends slow down water flowing to the jets. 

Also know that "Jet count" can also be inflated - some cheaper brands love to toss tons of tiny "bullet" jets into the spa to increase jet-count numbers because to the average consumer more jets = better hahaha.   The reality is these tiny jets can sometimes cause the skin to itch when they're running making it uncomfortable for the user.  My luxury 3-seater spa (which currently retails for around $10k USD) only has 14 jets total in the entire spa, but they are all full size large jets with enough pressure to give you a massage (when I close other jets in the spa and send full pressure to the lounger seat my wife finds those 7 jets TOO powerful and painful for her comfort lol)

Honestly "jet feel" is a very subjective topic and it's really impossible to determine that you will find one spa more or less comfortable than another spa without physically "wet-testing" a spa from that collection (doesn't have to be exact spa model, but should be something from the same product collection/tier).   Before covid wet-testing was highly advised and it was considered a red-flag if a dealer refused a wet-test.

Speaking of which, be sure to research the dealer thoroughly - you're often stuck with them for the duration of the warranty so be sure to read what existing customers say about the dealer (not the brand).  Find out what is covered under warranty, and more important - dispatch fees for warranty service (some crummy dealers only give you 6 months free dispatch before they try to charge $150+ for warranty service calls)

[CanadianSpaTech]

If you can't wet test but they have a running spa use the back of your hand and not your palm to get a better "feel" for what the jet will be like against your back/body

[Patterson]

12 hours ago, CanadianSpaTech said:

If you can't wet test but they have a running spa use the back of your hand and not your palm to get a better "feel" for what the jet will be like against your back/body

Thank you so much for taking time to reply.

 

[Patterson]

12 hours ago, CanadianSpaTech said:

If you can't wet test but they have a running spa use the back of your hand and not your palm to get a better "feel" for what the jet will be like against your back/body

Thank you so much for taking time to reply