Hi,

Just purchased a Sundance spa shell with no guts. I believe that is was a two pump unit, there appears to be two inputs and two outputs, plus a blower hose. There are 23 water jets and 16 air jets.

I am looking to purchase a Balboa VS510S spa pack. (Dual speed pump 1 + Single speed pump 2 + Blower + Ozone)

Based on this info, and pics attached, does anyone have suggestions on horsepower ratings for the primary and secondary pump? I don't want to go too small nor too big. Also looking for suggestions of how powerful of a blower pump I should get.

Also if anyone knows which pair of hoses should go to the primary pump and which pair should go to the secondary pump i'd appreciate it.

Thanks,
Stan

Sundance typically ran 4HP pumps with those tubs. The plumbing pair on the right is your primary, dual speed. The plumbing pair on the left is the single high speed. Confirm by blowing compressed air through the plumbing, the primary needs to be connected to the filter.