Pentair System with pool and spa as 2 seperate bodies of water. Ideal?


New member
Apr 30, 2016
Newport Coast, CA
Hello everyone!

Long time lurker, first time poster. You guys seem to always know the answers, so I am coming in for some help.

I have a 21,000 gallon inground pool in the backyard, and a spa in the center courtyard. Both are at the same level but currently it is being filtered and controlled as two seperate bodies of water. I have attached pictures of my pump system and was wondering if it is best to maintain them seperate, or if it is plumbed correctly that I can do a spillway and run them together?

Pentair system with easytouch controller, IC-40 SWG and single speed pumps.

Please let me know your thoughts!

Thanks so much!




TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
If you can arrange a spillway from spa to pool, then one setup is great.

The problem with plumbing them together without a spillway is that you have to carefully match the inflow and outflow of the spa so it never overflows or runs dry. You can't really do that. If the pool skimmer gets clogged up, then more suction than return will be directed at the spa and it will suck it dry. Or if a wad of leaves blocks the drain in the spa, it will overflow. Thus, without a spillover, you must have two systems so the amount of water coming from and returning to the spa is matched. It has to be, since it's a closed system.

If there's a provision to spill from the spa into the pool, then no problem. You set it up so a portion of the return and none of the suction goes to the spa and it will get mixed and flushed into the pool.