Popular hot pools now adults only after 7-year-old drowned.
A geothermal pool complex has increased safety measures, including banning under 18-year-olds, after the death of a boy in January.
Palm Springs hot pools in Parakai, northwest of Auckland, has hired two lifeguards, added a CCTV camera with a big screen visible from reception, and has become adults-only.
The changes come after a 7-year-old boy died in hospital the day after he was found unconscious at the bottom of one of the complex's pools.
No legislation governs pool safety, but the New Zealand Recreation Association has worked with the industry to create the independent assessment Pool Safe guidelines many businesses adhere to.
Palm Springs manager Shelly Walker said Palm Springs was not Pool Safe accredited, but now followed the organisation's guidelines "100 per cent" on the advice of WorkSafe New Zealand after the Government body began an investigation into the January death.
The pools became adults-only on March 1, Walker said, about the same time as the lifeguards were put on duty.
"The cameras were off our own bat. We decided even though we have a lifeguard patrolling, when they're looking at the top pool, they can't possibly be looking at the bottom pool. So this camera is always aimed at the biggest pool."
Walker said the popular destination had been known as the "family pool". She said there was some negative feedback after changing the policy to adults-only. "We needed to identify the hazards and eliminate them."
The big pool, which has a maximum depth of 1.8m, was a hazard to anyone under-18, she said.
"It was logical to eliminate as much risk to our customers."
Walker said families could still use Parakai Springs, a separate pool complex across the road.
NZ Recreation aquatic projects manager Tracey Prince described the moves by Palm Springs as positive.
"Having a lifeguard at the facility is a huge improvement. Having that supervision and someone who is able to provide immediate assistance is definitely a step in the right direction, as long as they are qualified."
Prince said there was no legislation forcing public and private pools to have a set number of lifeguards by ratio of customers. She believed most public pools had one lifeguard on duty per 50 to 70 swimmers, though some had more.
More than 140 of New Zealand's 214 public pools are Pool Safe accredited.
Its standards include operating procedures, emergency action plans, incident reporting, and that all serving lifeguards have up-to-date first-aid and practising certificates.
"The guidelines are thorough and have been developed over quite a few years."
A spokeswoman for Worksafe New Zealand said its investigation into the drowning was ongoing.
The organisation had outlined Palm Springs' responsibilities under the Health and Safety in Employment Act, including to identify hazards and take steps to eliminate, isolate or minimise them.