Auckland's pooiest pools can now be revealed.

The two pools with the highest number of code brown and vomit incidents were Onehunga War Memorial Pool and Lloyd Elsmore Pool in Pakuranga.

Figures released to the Herald on Sunday on Auckland Council-run pools show both facilities have been forced to close 29 times each between January and March this year due to contamination of the water.

The outdoor pool at Onehunga and the leisure pool at Lloyd Elsmore were the worst hit, said Auckland Council business manager of active recreation Alex Calwell.

Albany Stadium Pool was the next worst hit with 25 closures.

It was the hardest hit last year, accounting for 98 of the 581 pool closures across the public pools.

Calwell said the improvement at Albany Pool was most likely due to an educational campaign, which sought to raise awareness among parents and children of what to do during a code brown - a colloquial term used when children have an "accident" in the pool.

He said the rise of incidents at Onehunga and Pakuranga could be due to a rising number of patrons.

"Onehunga has probably had a pretty good summer just in terms of the outdoor pool, so their high number could just be volume of people coming through, it might be down to [the young family] demographic and it might be down to how they educate their customers who are using the facility," he said.

Calwell said toddlers and babies were the most common culprits.

"Usually, because they're not wearing a swim nappy which is our biggest bugbear.

"We've done a pretty heavy promotional campaign around wearing swim nappies for the under 3s and we've seen quite a significant reduction in the number of incidents," he said.

Cleaning up the murky waters was no quick or easy task.

"If it's a solid bit of faecal matter, we'll close the pool down, get everybody out, remove the offending item, then we will super-chlorinate the pool, so we will add extra chlorine, as high as we need to go based on the standard," Calwell said.

"Then we'll leave the pool, depending on the size of it, for about three to five hours."

The pool then went through its filtration process a couple of times and once complete, the pool was retested.

Once it came back within a normal range, the pool was reopened.

Calwell said whenever vomit or diarrhoea ended up in a pool, the facility could be closed for up to 24 hours which could be costly.

"If we were to close West Wave [in Henderson] down with 160 people in the pool area, we'd probably lose $2000 to $3000 that day, based on adults coming in and using the facility," Calwell said.

"The worst bit is more the community blowback from the loss of being able to use that facility," he said.

Calwell said people should inform pool staff immediately on seeing a code brown or other incident.

"Just come talk to us and we'll sort it out. Because it can be quite embarrassing for some people, nine times out of 10 you won't find the person who caused it, because the parents are embarrassed that their child has done that, they'll just whip them out."

Auckland Council spokeswoman Jenny Hua said such incidents caused significant disruption to customers.

"Auckland Council is continually trying to educate customers about appropriate use of the pools, encouraging young children to wear swim nappies and not to swim if feeling unwell or having eaten recently," she said.