If it had not been for a team of fast-moving staff and enough salt to fill a small house, the unprecedented floods in North Queensland would have destroyed the world's largest living coral exhibition.

"It was absolutely touch and go," Ashley Frisch said, the research and water quality coordinator at Townsville's Reef HQ Aquarium.

The iconic aquarium, which opened in 1987, is actually a living coral reef that is home to thousands of marine animals and considered a piece of the Great Barrier Reef on land.

But the recent deluge in Townsville was almost enough to devastate the much-loved tourist destination as the pouring rain diluted the salinity levels in the aquarium's tanks.

Water quality coordinator Ashley Frisch says the marine park was on the brink of disaster. ( ABC News: Rosie King )

"We've got an open-topped aquarium, which means rainfall lands in the tank, and over the last week we measured 1.4 metres of rain, which is more than we would usually get in a whole year," Mr Frisch said.

"Our reef tank is only 4m deep so adding 1.4m of fresh water on top of that is a major dilution — a 33 per cent dilution of the salt concentration in the sea water.

"There are no corals that can survive salinity levels that low and levels like that can also cause major mortality for our fish and sharks.

"We had an impending disaster and we needed to act rapidly to get some salt in there."

Enough salt to fill a small house

More than 1,100 bags of pool salt have been added to the water tanks at Reef HQ in Townsville. ( Supplied: GBRMPA )

By "some" salt, Mr Frisch meant an enormous 26 tonnes packed into more than 1,100 pillow-sized bags.

"We usually use a very high-grade salt but no one had that much in stock. We had to switch to emergency mode and use pool salt instead," he said.

"That's all we could get here in Townsville so hopefully it won't have any disastrous effects, and had we done nothing, everything would have died anyway.

"It was an emergency response and desperate times mean desperate deeds."

Finding that much salt, which Mr Frisch said was enough to fill a small house, was not the only hurdle.

"We've only got one ute here and there's no way we could have done it with just that," he said.

Business owners donated trailers and trucks to help transport the salt bags to Reef HQ. ( Supplied: GBRMPA )

"So we had business owners pitch in lending us trailers and small trucks — whatever mode of transport we could get our hands on we used.

"It was a huge team effort, and I think that shows just how much Reef HQ means to the people here. It's a North Queensland icon."

Once the salt started piling in, a team of 10 aquarium staff members worked non-stop in teeming rain to empty the bags into the aquarium's tanks.

However it was not as simple as pouring the bags into the main tank.

Each bag was added to a smaller tank where the salt was dissolved in water.

Once dissolved, the water from the small tank was allowed to flow into the main tank.

This meant there was an even concentration of salt for the marine animals.

Putting the animals first

Mr Frisch said the aquarium's employees worked for days during the disaster, despite their own homes being impacted by flooding.

"Right at the peak of the floods we were pouring 4–5 tonnes of salt in there each day," Mr Frisch said.

"And just like everyone else, we had staff members that were seriously affected by the floods but they kept coming in, through the weekend, working in the rain.

"I'm really grateful and proud of them for treating the aquarium as a priority.

More than 26 tonnes of salt have been poured into the tanks since the rain started. ( ABC News: Rosie King )

"I couldn't have saved this place on my own."

The steady flow of salt into the tanks has slowed but it has not stopped.

So far the marine life at the aquarium have not shown any worrying signs.

"Everything seems to be in good shape but we'll keep monitoring the salinity levels and adding salt accordingly," Mr Frisch said.

"If anything was going to be showing signs of stress by now it would be the coral.

"Coral is known as the canary in the coal mine because they're such sensitive little critters, but even they're holding together quite well."

The Reef HQ aquarium is a popular Townsville tourist destination. ( Supplied: Reef HQ Aquarium )

Still a waiting game

Mr Frisch has warned aquarium staff that they are not in the clear yet.

"It will be quite some time before we get back to a routine schedule and that's because the Ross Creek, which is just outside the aquarium, is where we get our salt water from," he said.

"I measured the salinity in there the other day and it was more fresh water than salt water so it's unusable for us.

"Typically we would get about 750,000 litres from there every two weeks but we won't be getting any for at least a month, maybe longer.

"So we're in water conservation mode. We're treating the water we have — this high salinity water — like gold because we need to hold on to it for as long as possible."

Ross Creek usually supplies a significant amount of salt water to the aquarium. ( ABC News: Rosie King )

If nothing else, the floods have given Mr Frisch confidence that he and his team will be ready for whatever else Mother Nature might hurl their way in the future.

"If we can handle this, we can handle just about anything," he said.

Editorial note 15/02/19: This article was originally published with a figure of 26 tonnes of salt being used. This was later amended to 2.6 tonnes, however that figure was found out to be incorrect. 26 tonnes is the correct figure.