The Giant Ocean Tank - what a beautiful and imposing exhibit. Impossible to miss during a visit to the Aquarium, the GOT rises four stories through the very center of the Aquarium, the pristine Caribbean water contained within bathing the Aquarium in an azure light.



Wait, what? Caribbean water? Isn't the New England Aquarium in the very heart of New England, home to Nor'easters and the Red Sox? Where does this warm, clear, and decidedly non-New England water come from?

Good question! (Well, of course I asked it, but still...)

The short answer is, we create it.

But that answer is unfair, it short-changes the truth. That crystal clear water is created through the dedication of an entire team of skilled technicians, men and women who work literally day and night to make sure the water that flows into, throughout, and out of the GOT is absolutely the best water the exhibit's inhabitants could ever hope for.

Like the wizard pulling levers behind the curtain in the Wizard of Oz, the Mechanical Systems Operators (MSOs) are the wizards behind the Giant Ocean Tank. Or maybe I should say below the GOT, for much of the magic happens in the very bowels of the Aquarium, far from the inquisitive eyes of the visitors.


The long corridors in the basement of the Aquarium, with its complex network of piping everywhere, reminds me of a submarine.

Mark, one of the MSOs, recently took me on a tour of what really goes on down there, and helped me connect the dots from when water enters NEAq, to when it bids it farewell.


MSO Mark surveys everything from his command post

Yep, that water starts its journey into the GOT straight out of Boston Harbor. Of course, it has to clean up its act before it's allowed to enter the inner sanctum of the GOT. It's just too cold, too filled with algae and sediments, and too - well, it's just not ready for the big time. But we all gotta start somewhere...


The intake pumps

Powerful pumps periodically draw water out of the harbor and into holding tanks in NEAq's basement via two massive intake pipes. I've been SCUBA diving down to the 'business end' of those intakes, out on the seafloor of the harbor, and it's pretty creepy to think about accidentally getting sucked into one of them. Luckily, we have a very strict safety protocol to ensure that could never happen!


If I ever was sucked into the intakes, you'd find me inside this giant strainer (the thing I'm leaning on). Fortunately I'm only standing next to it.

Once it's brought into the Aquarium, the water spends a good amount of time in "H2O charm school", where it's steam heated and filtered, filtered, filtered. I won't bore you with the technical details of the many styles of filtration we employ, just suffice it to say there's a LOT of filtration systems within the footprint of NEAq.


One of the GOT filter rooms.


Even Barbara, Husbandry Operations Manager, gets into the act. She's getting a little water time in one of the filter beds. Believe me, that's not an easy place to get into.

Once the harbor water has been made Caribbean-ready, it's finally allowed to mix with the GOT water. This water, which includes the 200,000 gallons inside the tank as well as about another 50,000 gallons that flows throughout the GOT's life-support system (LSS), is circulated every ninety minutes. That's right - the entire volume of the GOT is replaced every ninety minutes.


Here's a view of the main GOT pump and its backup

Powerful pumps draw this water out of the GOT, through yet more filtration, and push it all the way up to the fifth floor, ABOVE the top of the GOT, where - yes - it's filtered again.


Protein skimmers, part of the GOT LSS, a floor above the top of the GOT.

At this point the water is treated with ozone gas - a gas that's basically created by man-made lightning! Ozone is just one of the tools we use to help break down organic waste (aka 'fish poo').


This is the ozone generator dedicated to the GOT. It makes a big scary noise about every thirty seconds.

After protein skimming and a healthy dose of ozone, the GOT water thunders into a 26,000 gallon tank called the 'head tank' on the fourth floor, helping to oxygenate the water (fish need oxygen to live, just like us humans). This tank provides a reservoir for the GOT LSS, and because it's located four stories up, it enlists gravity to help propel the water back into the GOT.


This is where the water is dumped into the head tank.


Here I am at the entrance to the head tank (that black hole behind me). The pumps have been turned off so Dan and I can do an inspection dive in the tank.


That's Dan crawling down into the tank.


I brought an underwater camera with me to inspect the tank. The sound is pretty cool.

Once out of the head tank, the water flows down another pipe, all the way into the basement, where it then flows UP into the bottom of the GOT. That's right - the entire weight of 200,000 gallons of water, and four stories of tank, sits above the machine shop of our facilities guys.


MSO Matt in the machine shop under the GOT. He's standing beneath over 1.6 MILLION POUNDS of water! Those big red pipes going into the ceiling are the intake and discharge lines for the GOT.

Well, that's about it. Harbor water gets dressed up, introduced into the world of the GOT, then after a good long stint circulating within the Aquarium, it's treated and released back into the harbor, probably cleaner then is was when it came in.

I suppose if you think of it like that, NEAq is kind of like a health spa for water...

So next time you visit the Aquarium and marvel at the Giant Ocean Tank, you'll know a secret. There's a team of wizards busy behind the scenes pulling levers and pushing buttons to make it all happen.

Safe diving.

- John


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