Help - Spa water drains back into pool when pump is off

Hi all - new here, and I am having a pool problem.

We recently purchased a house with a pool, and we have no experience with them at all. So far I have been getting by with advice from friends/neighbors.

This pool has a built-in spa that in designed with a water fall down about 2.5 feet into the connected pool. When the pump in not running, the water slowly subsides from the spa into the pool. It hasn't been a big problem as the water in the spa comes right back up when the pump runs twice a day. Now, however, it is getting to the point where the plaster is exposed, and today it was down below the jets in the spa.

My pool equipment is all several years old, and it is all hayward. The pump is a Super II. I have read elsewhere that it might be a check valve, but I don't know where to look for this or what it would look like. It makes sense that it would be a check valve, so hoping I can locate it and replace it.

Any help in pointing me to the proper place would be appreciated. Thx.

I too am new to my pool and spa, but I had set the valves manually with the switches on the back. So when the pump would turn on it would change the location of the valves automatically and it would cause the same problem. Now, I rarely touch the switches on the backs of the valves, and if I do, I make sure I set them back. My pipes are labeled, pool suction, spa suction, pool return, spa return, so I was able to figure out what was going wrong and why the spa was draining below the jets. My spa is about the same level as the pool, so I had the waterfall going the other way!

I am sure an expert will step in and give you a better answer. Can you take a picture of your setup? I can do the same and illustrate what I am talking about.

Your situation is typical of new owners of old pools with complex piping (ie, pool + spa). It's hard for us to trouble shoot such pools remotely, but if you post pictures we may be able to help. (Use Flickr, Webshots, Google Drive, etc, and post the link to the pix.)

BUT . . . your best bet is to hire a good local service guy to come check your pool out AND show you how.