Dye
Testing

Dye testing is a leak detection method where concentrated, colored dye is released near suspected leak points in the pool. If there's a leak, the escaping water pulls the dye into the crack or gap — providing visual confirmation of exactly where water is leaving the pool. If the dye disperses without being pulled anywhere, that spot isn't leaking.

Pool leak detection dye is heavier than water and stays together as a visible thread when released. When you place it near a leak, water flowing out of the pool pulls the dye toward the leak point — you can see the dye being "sucked" into the crack or gap. The pump must be off so the water is still; any dye movement is caused by the leak itself.

Yes. Professional pool leak detection dye is non-toxic, non-staining, and disperses completely within minutes. It won't affect water chemistry or damage any pool surface — plaster, pebble, fiberglass, or vinyl. The small amounts used during testing are undetectable once dispersed.

It's not recommended. Food coloring disperses too quickly in water — it clouds and disappears before you can see where it's going. Professional pool dye is engineered to stay together as a cohesive thread, making it visible long enough to track its movement. For small, subtle leaks (which are most common), food coloring won't work.

Most leaks occur where something penetrates the pool shell: skimmer throats (the most common location), light niches and conduits, return fittings, main drain covers, and cracks in plaster or tile. These are the areas we dye test first because they're the most likely culprits.

No. Many cracks — especially small surface cracks or shrinkage cracks on steps — are cosmetic and don't leak at all. Dye testing is how we determine which cracks are actually losing water. We've seen long cracks that don't leak and tiny cracks that leak significantly. Only dye testing gives you the answer.

You can try, but it's trickier than it looks. You need the right dye (not food coloring), completely still water, and the ability to position the dye precisely near suspect areas — including underwater areas like the main drain that require diving. Professional leak detection technicians also know where to look based on the symptoms, which saves time.

No. Dye testing is done with water in the pool — that's the whole point. The water must be still (pump off), but the pool stays full. Most structural leaks found by dye testing can also be repaired underwater without draining.

Dye testing finds leaks in the pool shell — skimmers, lights, fittings, and cracks. If we dye test all suspect areas and don't find the leak, it's likely in the underground plumbing (pipes between the pool and equipment). That requires pressure testing, which is a separate diagnostic method we also perform.

Often, yes — especially for structural leaks in skimmers, fittings, light conduits, and small cracks. These can be sealed with underwater epoxy or pool putty without draining. Larger structural repairs or plumbing leaks typically require scheduling a separate repair visit.

Very accurate for confirming leaks in the pool shell. When dye gets pulled into a crack or fitting, that's definitive proof water is escaping through that point. The only limitation is that dye testing shows you structural leaks — leaks you can physically see and access. Plumbing leaks underground require pressure testing to identify.

Yes. Dye testing is a standard part of our comprehensive leak detection service. We inspect the pool shell (using dye testing) and the plumbing system (using pressure testing) to give you a complete picture of where water is being lost.