- I got an email from an aquarium,
and it changed my mind about aquariums.
Because biology and zoology... never really interested me all that much.
For me, somewhere like this, The Deep in the city of Hull,
wasn't somewhere I'd visit because, yes,
important for conservation, vital for science,
but... it's just some fish, right?
But then they sent me an email and asked me if I'd be interested
in looking at their life-support system.
Now, I've only ever heard the words "life-support system"
in the context of spaceflight, either realistic,
like the oxygen scrubbers and water recyclers
on the International Space Station,
or in... less realistic situations.
- Life-support systems sustaining on emergency.
- But The Deep, here?
It has a life-support system.
- We are a closed system.
So, much like your spaceship, we are isolated.
There's no input or output to the oceans whatsoever.
The water inside that system or exhibit is constantly recirculating
between the exhibit and the life-support system.
So, everything that we have here, we have to control,
including making our own seawater.
The water starts off, just as it would in your home, out of the tap.
Now, the water is very, very hard around here.
It's lots of calcium carbonate in the water,
so the first thing we have to do is soften it,
so that is the removal of that calcium and magnesium ions from the water.
So, these are full of an ionic resin,
and they scavenge those ions out of the water.
We don't want calcium to build up
in our life-support systems, on our heating elements.
So, what we're left with, in this great container over here
is roughly 30,000 litres of softened water
that has gone through this reverse osmosis machine.
It's basically pumping water across a very fine membrane
under very high pressure to give us very, very pure water.
To that pure water we then add artificial sea salt.
We then pump it around where needed around the building.
So, this is a really good example of a small-scale life-support system
that we would use for some small stand-alone tanks,
like this research system here.
Now, this has got all the components of a life-support system
that you would normally find in an aquarium like this,
and this is all scaled up on a huge scale for things
like our large 2.5-million-litre system.
What we have at the back here, that's a foam fractionator.
So, all of these micro bubbles that are being injected
at the base of this foam fractionator are scavenging organic molecules.
Now, these molecules and compounds are actually hydrophobic.
They don't like water.
And what they want to do is they want to adhere
to the surface of this micro bubble.
And they rise to the surface,
and we then remove them via the cone at the top.
This is a bio tower.
So, fish excrete ammonia and urea.
Now, we have to convert those to less toxic forms.
Inside here, we have a lot of bio-balls, and that is a huge, huge surface area.
The bacteria that live on these bio-balls
are converting it through to nitrite, then to nitrate,
and we can then complete that process by reducing that to nitrogen gas,
which can just off-gas into the atmosphere.
We've got the sand filtration here.
So, water enters the top of this unit. It goes through a bed of sand,
which scavengers out all those particulates in the water,
and then exits the bottom clean.
One of the last steps in the life-support process is ultraviolet light.
It breaks down cell membranes.
So, we're really looking at anti-microbial action within these units.
So, water is constantly recirculating
between the life-support system and the exhibit.
- As I talked to the team here, I realised that,
sure, you can call this an aquarium,
but you could also call it "a spaceship for sharks".
You've got creatures contained in a higher pressure environment.
And okay, it's not the vacuum of space out here, sure.
But if these walls are somehow breached, the environment inside will spray out.
And if it's not fixed quickly, those fish are dead.
And if that environment isn't controlled and maintained constantly and carefully,
they're also dead.
And that takes a lot more equipment and a lot more precision
than you might think.
- So, just as we have a small foam fractionator
on our smaller life-support systems,
this is the scale of this skimmer on our large system.
Now, this is part of the building, it's so huge.
Now, a key part of maintaining this is making sure
the mixture of gas is correct that we're pumping into it.
So, here we have a gas panel.
Now, this is where we alter the mixture of air and ozone
that is going into the super-skimmer.
So, that's helping to break down those organic particles, molecules,
so that the skimming can be that much more efficient.
So, we're going down into the heart of the building now,
into the basement, and that's where the really large
life-support equipment is located, some of which is so large
it forms the fabric of the building itself and the pipework is built into the ground.
So, we're now three floors down,
and we're only just at the base of the super-skimmer.
We saw the cone right at the top. Now, we're right down at the base,
so it just gives you a sense of scale for how big that super-skimmer actually is,
and how much a part of the building it actually is.
The water then comes back out of the super-skimmer
and enters our giant sand filters.
We need to remove all the particulates out of the water,
those little pieces that you might see floating around,
bits of food, things like that.
So, here we have some very large banks of UV.
So, water is constantly passing and exposing microbes to that UV light.
And then the last step in the process
is the huge pumps over there take the water
and pump it back into the main exhibit
and we start the whole process over and over again.
It happens constantly,
and the water is going round and round completely about once every three hours.
So, here we are above our main exhibit, Endless Oceans.
Now, this is a tropical marine system.
It's 2.5 million litres. It's 10 metres deep.
And in here is where we keep all of our really key species,
including some that are unfortunately now critically endangered in the wild.
We do call it a life-support system
because it is doing exactly that: it is sustaining life.
We're controlling every single water parameter
in order that the species that we're keeping here are thriving.
We are responsible for every single life at The Deep.
- Thank you so much to all the team at The Deep in Hull.
There's a link to them down in the description.
And thank you to my dive cameraman, Tom!