Spa draining till level with pool

[Mnicholls]

Hi there,

Just bought a house with a pool. Had previous pool without many issues. This one will be more of a project.

Anyways, I have noticed the elevated spa drains down till equal with pool overnight. I believe this is usually due to faulty check valve.

I am attaching a photo of my setup. The previous owner replaced the heater just before selling house and there is a brand new check valve before the chlorinator. But there’s no check valve on the spa return line ( far left). Is that missing check valve the likely culprit? The pool is almost 30 years old.

Any advice would be appreciated!

 

[ajw22]

It doesn't look like you have a check valve on your spa return line.

Hard to see every line closely in your pics. Look for an old style check valve as shown in this thread:

Problem solved: Pump turns off, DE migrates back out skimmer & drains

Not here with a question. Instead I'm sharing with readers (esp DIYers) how I solved my pool's mysterious problem and what I learned. This forum has been very helful to me. Keywords would be: D.E. backflow skimmer drains D.E. not sticking grids fall off grids plume cloud pump shuts off back...

www.troublefreepool.com

Really it is not a major problem. Spa drains back to pool at night when pump turns off and fills once pump is turned on. Probably been like that for 30 years.

Why do you have the spa and spillover always running? It will cause your pH to increase from the aeration of the spillover. Although it does not look like you have any automation to run the spa a few times a day to keep the water fresh.