I have an idea where my pool is leaking but need confirmation from experts!

[doobs21]

Hi, I have a pool/spa combo (spa spills over to pool). I'm losing about an inch per night and I have run the bucket test.

At first I thought the pool was losing water but upon further investigation, I noticed my spa was losing water at night (with pump off). I have my my pool skimmers taking in water and for return, I have it go both to the pool and the spa. So my hypothesis is that there is a leak in the drain of the spa that is losing water every night when pump is off. When I only circulate the spa (suction and return only in the spa), there is little air bubbles getting into the pump but not when I suck in from pool and return to spa/pool.

I hope I explained this properly as it is a little hard to explain. I have 2 questions I'm hoping I can have answered:

1) Can I plug up the drain of the spa somehow? I believe this would stop overnight water loss. I never use the drain of the spa and all water to the pump comes from the pool.

2) Is there a different way to test whether or not this is actually where the leak is coming from?

Thanks in advance for any advice.

 

[mas985]

While you may have a leak, the lowering of the spa level could be something else. Is the spa elevated? If so, are you sure it isn't leaking back into the pool. That can happen with an elevated spa and a bad check valve.

Assuming the spa is the thing that is actually leaking, the light is the usual suspect. But if you want to check the suction line, you need to isolate both sides of the line. You can use a pipe plug on the MD side (remove covers) and if there is valve on the pad side, that should work ok.

 

[doobs21]

The spa is elevated and I did have a bad check valve before but thats been replaced and resolved.

I didn't even think about the spa light. Thanks, I will google a bit about how to check/replace the spa light. And also, thanks for advice about pipe plug. I will try that next if spa light doesn't work out.

 

[mas985]

By spa light, I really meant the niche. The plastic niches leak a lot because of the weak point in the conduit connection. They are also very difficult to fix it if is leaking. You may have to epoxy the wire into the back of the niche. Sometimes a special rubber plug can be used to stop it from leaking.

A dye test can be used to determine if the leak is from the light or the MD.