LEAK/EVAPORATION TEST
To make sure your pool is leaking & to know how much, it's a good idea to set up a leak/evaporation test. In this order....
- With the pump off & the pool water fairly still, mark (with a pencil or a carefully placed piece of tape) the water level at the skimmer mouth or adjacent tile. If the pool has solar panels make certain that they fully drain back into the pool before marking the water level. Also, make sure to manually valve off any other body of water (such as a spa or fountain) that normally drains back into pool when the pump shuts off. This will also help to isolate the spa or fountain etc for its own leak/evaporation test.
- Take a 2 gallon or larger bucket & place (with a marker) a thin horizontal line less than 3/4" down from the inside top edge of the container. (Many pool owners wonder why their tests didn't run correctly after only filling their test bucket half-full--remember...less than 3/4".)If the pool is heated, make sure the container/bucket is made of metal to better conduct the pool water temperature. Fill the bucket with pool water up to the line & place it on the top step in the pool. Use bricks or other support to slightly raise the bucket if it is in too deep & wants to float away.
- After a normal 24 hour cycle, check the mark in the bucket & at the skimmer. There will be no appreciable difference(within a 1/16") if the pool has no leak--rain or shine. 12 hour tests can be performed using the above techniques and should be initiated in the early evening. Dusk till dawn tests suffer from less water loss due to evaporation.
- Differences of more than 1/16" (or 2/32") in the Summer, between the bucket & the pool water level within 24 hours, indicate leakage. More than a 3/32" difference during the Winter would indicate leakage--a plastic bucket cannot efficiently transmit relatively warmer pool water temperatures during cooler months. (An aluminum container transmits better while a stainless steel container transmits slightly worse--than plastic).Note..., do not expect accuracy beyond a 24 hour test--especially during large temperature fluctuations. Though this is a good effort, you can never consistently duplicate (in the bucket) the micro-environment (cross-breezes, water circulation, pool finish color etc) present in/at the pool.
If there is not a significant difference between your test container (control test bucket) and your system, then you most likely don't have a leak. Reference our Knowledge Base to look at evaporation tables and check out our FAQ for detailed information concerning the 4 major evaporation factors.