Fata-meafou said his partner was working, but the couple have a 2-year-old daughter and will struggle to cope on the reduced income.
"We are paying rent," he said. "I think we probably could cope, but that will be just scraping it."
His brother Misialofa, a father of five, has been on dialysis since last year when his kidney function dropped to 7 per cent after several years of high blood pressure.
"The main symptom was tiredness," he said.
He was placed on the waiting list for a kidney transplant from a deceased donor and the family of five brothers gathered to talk about it.
"My youngest brother came forward, but he had some health complications," Misialofa said.
"Then my second-youngest brother [Lima] came forward. It took nine months to do the tests, they do a thorough check through the body. He's pretty healthy."
Lima said his life had changed since he and his long-term partner Julia had their daughter Eljaye, named after the initials of their first names, two years ago.
"I was the black sheep of the family. I enjoyed my life. I didn't really care about the consequences," he said.
"But as time got on and your friends start having children and your friends become grandparents, you start to think, 'Oh, let's try and have a baby together'."
He said Julia cried on the day he went into Wellington Hospital to donate his kidney.
"I wanted her blessing before I went into the operation. I've known her for 19 years so I know that it's something she was just scared of, but I still wanted to do it," he said.
"I'm grateful to have done what I've done. It's not just me, it's the surgeons and everybody else who had a part to play in it."
Bishop said he brought in the new law to pay organ donors for all the income they lose through donating an organ to boost New Zealand's low rates of organ transplants.
"People who donate live organs are heroes," he said. "They are actually sacrificing a part of their body to heal someone else. At the moment it's very unfair that they have to go without their salary for that period of time."
The law allows for up to a year before it comes into force to allow time for the payment system to transfer from Work and Income to either the Ministry of Health or district health boards - details that Bishop said were still being determined.
He said he hoped the law would actually come into force in the next two months. Lima Fata-meafou and others who have donated organs since last December will then have 120 days to apply to either the Health Ministry or a district health board to get a backdated income top-up for the period they were off work.
Counties-Manukau District Health Board renal transplant coordinator Denise Beechey said most people who donated kidneys were family or friends of the recipients, but some people donated kidneys anonymously to anyone in need.
"In Counties this year we've had one person donate anonymously. Last year there were about three," she said.
"It's an altruistic act which is an extremely generous thing that some people will do."
Kidney statistics
2370 New Zealanders on dialysis with final-stage kidney disease.
600, including 180 in Counties-Manukau, on the waiting list for kidney transplants from deceased donors.
73 received kidneys from deceased donors in 2015.
74 received kidneys from living donors in 2015.
Sources: Live Kidney Donation Aotearoa; Organ Donation NZ.
