Hot tub control

[colinn]

Good morning. I ran my hot tub for the first time last night and I noticed something that was unclear to me. I don’t have automation so I manually turn valves myself. I changed the position of the suction side valve to pull water from the hot tub and set the valve on the return side to flow only into the hot tub. My concern is as water is being circulated to and from the hot tub, how is the water that is being splashed over the hot tub into the pool from the air blower being replaced? I ended up opening the suction side valve slightly to pull mostly from the hot tub but also slightly from the pool to compensate for the water that is splashing over the hot tub to the pool. What is the correct way for this to work. I hope my explanation makes sense.

 

[mktee]

Water splashed outside the spa will not be replenished when in spa mode. Most spas are set up this way. So if you lose water when using the blower you would need to draw from the pool as you are doing. Sounds like your blower is turbocharged. I do not have a blower in my set up but have heard others talk about a valve on the blower pipe that can be opened so not all the air goes to the jets.

 

[DrewLG]

how is the water that is being splashed over the hot tub into the pool from the air blower being replaced? I ended up opening the suction side valve slightly to pull mostly from the hot tub but also slightly from the pool to compensate for the water that is splashing over the hot tub to the pool.

That was a good idea, although it does make it harder to heat the spa.

The usual solution to this problem -- and to a related one: How does the spa get fresh chlorine? -- is exactly opposite what you did: Instead of letting a little water be pulled from the pool while the spa is running, let a little water be pushed to the spa while the pool is running.

There are two ways to accomplish this, illustrated in the photos below. My valves are automated, so they'll look different from yours, but this should give you an idea of what to look for anyway.

The first way is with a bypass pipe to the spa return, with an inline valve (in the red box) to adjust the flow to the spa:



The second way is by adjusting the pool/spa return valve so it doesn't completely close off the spa side when it's switched to the pool side. You can see here that the return valve isn't turned all the way to the pool side in pool mode; there's an internal stop that keeps the spa side slightly open: