Chasing down a leak

[chawkins99]

We have a 25'x40'x3'6" 25,000 gallon gunite pool which is at least 20 years old. The previous owner had done DIY repairs over the years. Basically draining and patching it every 2-3 years.

We knew it was leaking but had never quantified it until I converted it to salt water a few weeks ago. From the salt levels I determined we were losing 750-1,000 gallons per day.

We then decided to turn off the fill line and the pump and let it sit. After a week, we had lost 6.5 inches. So, definitely a leak. Just not sure where. So decided to let it keep dropping. After 2 weeks, it seems to have stabilized just below MOST of the returns. There are still 2 returns below water level but it doesn't seem to be going down now.

Looking for ideas on tracing and fixing the leak.

 

[Texas Splash]

At this..at point, I would look at the following:
- Inspecting the return jets just above the waterline
- The entire wall (liner) perimeter of that new waterline
- Is there a light (if installed) at that same height? That could be another suspect area

Now that you've narrowed-down area, consider increasing the water again slightly and testing carefully with some food dye. It doesn't take much of a tear to cause problems.

Leak Detection

A number of things can cause leaks in your pool. You can learn tricks for leak detection and how to pinpoint where your pool is losing water.

www.troublefreepool.com

 

[chawkins99]

Thanks for the suggestions.
It has 2 lights. Both are still underwater so I don't believe those are the culprit. I'll check the walls and look at the food coloring option.