The Autofill Problem
An automatic water leveler is designed to maintain pool water level by adding water when the level drops below the float set point. A pool with a significant leak may have an autofill running almost constantly - and the customer never notices because the water level looks normal. The autofill has masked the loss completely.
This is one of the first things to ask about during the intake call: does the property have an autofill, and when was it last checked? If the answer is "yes, we have an autofill" and "it seems to run a lot lately" - that is a significant diagnostic clue before the evaluation even begins.
Isolate the autofill before measuring water loss
Turn off or isolate the autofill before any water loss observation begins. A water loss measurement taken while the autofill is running is not a measurement of pool loss - it is a measurement of the autofill's behavior. Isolate first, then observe.
Observe real pool water loss with autofill off
With the autofill isolated, the pool water level will now reflect actual losses - evaporation, splash, and any structural or plumbing leak. Compare to the bucket test baseline over the same observation period. This gives the true loss rate that was hidden before.
Inspect the canister assembly and connections visually
The canister unit itself, the float valve, the supply line connection, and the discharge point where water enters the pool or skimmer are all potential leak points. Look for wet areas around the canister, mineral staining indicating past water movement, cracked canister bodies, and loose fittings.
Dye test around pool-side connections
Where the canister line connects to the pool or skimmer body, dye testing under calm conditions may show whether water is moving through a crack or gap at that connection. A micro-fissure at a fitting connection may not be visible but can be revealed by dye movement under the right conditions.
Pressure test the canister line if safely isolatable
If the canister line can be plugged and isolated, pressure testing reveals whether the line itself holds. An underground canister line with a micro-fissure will show pressure drop during the test. Document the isolation achieved, the test pressure applied, and the result.
Always ask about autofills. The intake call should include this question every time: does the pool have an automatic water leveler? If it does, the autofill gets isolated before any water loss measurement begins. An autofill running constantly is a clue, not a solution - it tells you the pool is losing water, not that the water level is fine.
Learn to Spot the Hidden Variables That Change the Whole Diagnosis
LBA teaches autofill protocol, intake call questions, and water loss methodology that finds the real problem - not just the obvious one.
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