- 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!
