Coldwater Marine Aquarium Build

Hey everyone,

So, i'm gonna start a coldwater marine aquarium, based around the North Sea here in the near future. So, i'm going to give you guys a little sneak peak, of how i'm planning the system to be like. I would really like some feedback if you guys have any, so lets get started!

Where would you get the fish from?:
Well, i have been working at the North Sea Oceanarium for one week as a practical worker. I've been working with a marine biologist, some zoologists, zookeepers and things like that. I got to know alot about the North Sea, aswell as some information on the fish like viviparious blennies, seahorses, sea pipes, sea robins, flounders, sea anemones, corals and big fish like the ocean sunfish. I'm going to talk a little more closely about the North Sea Oceanarium later in this topic, and i'm gonna explain what i've done out there. I've been able to try pretty much everything, except diving (Because you know, its illegal when i dont have a diver certificate). But they told me, that if i wanted to start a coldwater marine aquarium, they would love to give me some of their fry like red spotted catsharks, sea robins, flounders, pollock, and all kinds of stuff, aswell as crabs, sea stars, urchins and lobsters. So, lets go over some of the things that I want (livestock), here are some pictures for you guys:

Red Sea Robin (Picture posted by atomjack on tumblr):


Flounder (Picture taken from Wikipedia):


Small Spotted Catshark (Picture taken from Wikipedia):


Pollock (Picture taken from theguardian.com):


European Sprat (Picture taken from Wikipedia):


Swimming Crab (Picture taken from fugleognatur.dk):


Coldwater Sea Anemones (Picture taken from bfn.de):


Viviparious Blenny (Picture taken from flickriver.com):


Common Starfish (Picture taken from Wikipedia):


So lets talk about some of the species. I know alot about them, since i walked around with a zoologist called Bjørn, and he told me everything i needed to know about all these different species and other species aswell. For example, something i find really unique, is that the viviparious blenny (By the way its a blenny, that is kinda awesome right?) are actually livebearers. They give birth to live fry. And they breed often. Imagine a bicolor blenny, just alot more long, almost like an eel, which is why its called "ålekvabbe" in danish which means "eel". They have a very long tail, and they're very active. They swim around constantly and are rather easy to keep. They are also delicious to eat, but apart from that, they get to be about 50cm. So, gotta get some small ones! The swimming crabs are also really unique, since they swim around with their two legs at the back. It looks ridicilous! But they are awesome, and they scavenge the tank for food and they stir around the sand too.

Also, the flounder. One of my all time favorites. Whenever i've been to the beach as a small kid here in Denmark, i remember always seeing flounders at the bottom of the sand, and sometimes they would just stick their eyes up above the sand. These guys are awesome, and out at the North Sea Oceanarium, they managed to breed atleast 300+ fry. The fry are funny enough very active and swims around constantly, where as the adult ones seem to be more calm and quiet. The adult ones doesnt need to be fed more than 3 times a week with some mussel or mysis, where as the small ones needs to get feed 3 times a day! Then, there are coldwater anemones. These things just look awesome. They had TONS of them out there, and it wouldnt surprise me if they would actually give me one or two of them. They split off quite often, and they thrive easily by just getting some plankton in a smaller tank. Bjørn told me, that they dont feed them anything else than mysis that might land on top of them.

So lets quickly talk about the Sea Robins. These fish are my absolute favorites. They are beautiful, looks really unique with the two circular fins on the sides and they are very active fish aswell. They are actually rather easy to keep, since they are pretty hardy, and they usually tend to eat small pieces of fish, mysis and mussel. They are extremely beautiful, and in danish we call them "Knurhaner" english translation: "Purrhen" because when they put air into their swimming blatter, it says a funny sound, almost like a cat purring. Very unique indeed. But these fish get huge, they get to be up to 75cm. Man, they even got some beautiful big ones in the oceanarium tank!

So for now, thats just some of the livestock that i plan having, now lets go over the tank, shall we?

The Setup:
I plan on getting a 75 - 90 gallon tank. I wanna go big. These fish can get extremely big, but when they get up to a huge size, i can give them back to the North Sea Oceanarium, and my fish can ACTUALLY be in a public aquarium, how cool is that?! Aswell as that, i want it to be a pretty wide tank, to make sure that if i get any sprats, they can have lots of wide swimming space for schooling, which they usually do in the wild. This is definitely going to be a challenge, because the water has to be around 11 - 12 degrees celsius, depending on the species that i'm going to keep. Some species from the North Sea thrives in deeper waters, and often needs all the way down to 8 degrees! Man, i'm gonna freeze just by cleaning the tank. However, i know how to keep all of these different animals, since i have been working with all of them at the North Sea Oceanarium. So, for this reason, i need to keep the tank cool, so i need some sort of cooler, to keep it down to atleast 12 degrees celsius, because these fish can NEVER thrive in warm waters without dying right away. I remember the oceanarium tank at the North Sea Oceanarium, where we always checked if the water was too warm. It could never get over 16 degrees, because then the ocean sunfish could take damage from it.

I'm gonna go with some basic lighting for this tank, not anything special, because i dont plan on getting anything photosynthetic other than some basic seaweed. The corals and sea anemones in the North Sea are all non-photosynthetic. So, maybe just some DIY LEDs that my dad can make, would be an easy and cheap option for an awesome looking tank. I plan on getting a skimmer, since i need to get some of all that waste out of the water, aswell as running carbon. Although, i do expect some of the seaweed to suck up some of the nitrates and phosphates in the tank. I'm gonna get some pretty intense flow aswell, might order some strong Hydor pumps, to blast out the tank. Cause remember, this is the atlantic North Sea, there are waves bigger than my house. If i'm gonna keep sprats, they probably will try to jump out, so gotta have something to cover the top of the tank.

The Aquascape:
I plan on getting some rocks, that will be placed in a way, so that there will be caves and small cracks where the fish and crabs can hide. I plan on getting some seaweed on top of the rock, and close to the sand bed (Yes i'm gonna go with some very fine beach sand, might go collect some from the beach to make it extra natural and like a true biotope). Although, i do want lots of open sand areas, because if i'm gonna keep flounder, i have to get some open areas with rather deep sand where they can bury themselves. Thats also why i might epoxy the rocks together, and place them on the glass, to make sure that the flounders wont make it all tilt over.

I might place some shells here and there, and get some hermit crabs aswell. (Yes, there are these sandy/brownish huge hermits in the North Sea). The aquascape is honestly not going to be something special like in a normal coral reef with lots of color and stuff, because the cold waters are typically pretty boring at that point of view, but the fish are awesome! So, rocks, fine sand I collect at the beach and some seaweed.

What are you gonna collect yourself?:
Some few sea anemones are probably what i'm gonna collect myself, aswell as seaweed and different varieties of crabs. I might find some urchins too. But we'll see. Can only collect in the summer, because if i'm gonna jump in the water in winther, my legs are gonna freeze off, so no no no! Aswell as that, i'm gonna collect natural rocks and sand to get that biotope feel to the tank.

Feeding?:
All of these fish are very picky eaters when it comes food. Some of them eats pellet food, which actually a danish company produce right next to the North Sea Oceanarium next to their research facility. But the most healthy way is to feed them some mysis and mussel everyday, where you might include some mackarel or pellet food every now and again. But frozen or live food is typically the best for these fish. Even the ones that they've bred in captivity, are still picky.

What is the North Sea Oceanarium?:
Now you guys have heard me jibber jabber about this place for this whole topic, so i guess i need to tell you guys about it. The North Sea Oceanarium is located in Hirtshals, Northern Jutland in Denmark, and is often visited by many danish people, aswell as germans, swedes and even some polish people were out there too. Many danish schools visit it aswell, to learn a little bit about how the North Sea is. But we'll get back to that later.

What is the North Sea?:
If we take the map right here, you can see the North Sea between the UK, Denmark and Norway (Picture taken from Wikipedia):



The North Sea is huge in the fishing industry of northern europe, where fishers are gonna be able to find big and delicious fish like cod, mackarel, tuna and herring. The North Sea is a coldwater marine environment, consisting of low temperature water, and deep waters. Close to Norway, the water can be as deep as 725m at the highest. There are even coldwater reefs in the North Sea, and some are not even fully explored yet. But deep down in the waters, you'll be able to find NPS gorgonians and other non-photosynthetic corals, sponges and anemones. The animals down there are creepy too, there are for example the king crabs, that can get as wide as 2m with spread legs and claws! (Picture taken from Wikipedia):


Back to the North Sea Oceanarium:
The North Sea Oceanarium is northern europes biggest aquarium, consisting of many different aquariums showing many different species from the North Sea. The "biggest" oceanarium tank, which is in the north sea oceanarium is 4,5 million liters (approximately 1188774,236867832 gallons, yeah i know) is the big attraction from this public aquarium. It contains the popular ocean sunfish, which is extremely hard to keep. The North Sea Oceanarium was in fact the first in the world, to keep these fish successfully and long term in captivity. Their oldest ocean sunfish, died a couple of years ago, due to a huge fire that burned the whole oceanarium down in 2003. It burned down because of a towel that was dipped in oil (Dont tell me what they were doing). So they had to rebuilt it. They recently got 4 new ocean sunfish, 3 of them died due to their normal behaviour of scrapping their bodies towards the glass. One of them is still alive and well, but was just injected with antibiotics, because it had wounds with infections because of the fact that they scratch themselves on the glass. What Bjørn told me, was that the ocean sunfish wants alot of swimming room, and it think it can continue in one direction, since they're used to swim in strong currents, to eat jellyfish. It will then sometimes continue into the glass and hurt itself by scratching its delicate skin. This can cause some pretty intense infections on the fish. The ocean sunfish is really special, and one of the most hardest fish to keep in captivity. Here is a picture of the old ocean sunfish that died in the fire in 2003 which was the oldest ocean sunfish ever kept in captivity (Picture taken from Wikipedia):



If you're one of my subscribers on youtube, you'll know that i've made 2 videos on the North Sea Oceanarium, with footage behind the scenes, aswell as a show of different displays and species at the public aquarium. You guys should feel pretty special, because you would NEVER be allowed to do this normally! But i love you guys, so gotta show you:

Working at the North Sea Oceanarium:

The North Sea Oceanarium:

But, how did you get out there?:
In 9th grade, all students have to go do some practical working, to go and try how its like having a job. My dream job is being a marine biology, and it has been that for many years now. I have a huge passion in aquatic life, and have kept aquarium for soon 7 years. I made a video for the North Sea Oceanarium to really stick out, because they would NEVER get any practical workers from 9th grade normally. So, i made a danish video, which you guys actually can see here, but you wont understand what i'm saying. But i'm basically just showing my aquariums and telling about my experience and my dream job. They immediately accepted and i was so happy. I was the YOUNGEST worker that has EVER been out there, so its a huge honor! It was amazing, got to meet their aquarium leader guy, called Martin, who by the way has a 2000 liter coral reef tank that said to me that i was awesome and he really thought it was fantastic that a person in my age already knew what to do later in their life, and stuff. So that is awesome. I might actually get a summer job out there aswell, because they have to tear down their oceanarium tank do to a scratch in the glass (bad news). So, yeah that is how i got out there, and its... Crazy! Its unbelievable to me, and it was an experience that i'm never gonna forget!

My application video for the North Sea Oceanarium:

UPDATE:
I will ask the North Sea Oceanarium if i can get a lemon sole, some swimming crabs, and about 3 or 5 viviparous blennies. My idea with this setup, is to get a fully working ecosystem, with fish and invertebrates that actually benefit the system. For anemones, i'm probably gonna get a filter feeding anemone and some seaweed to decorate the tank. Now, i made a few drawings and pictures for you guys, so you can see what i want this to look like. So a lemon sole is a little bit smaller and longer than a flounder, they're often known in Denmark for tasting good, but they are also rather expensive. They stay down at the bottom, and dig themselves under the sand. They are very inactive fish, and dont need a very big aquarium, since they mostly just sit at the bottom all day long. What this will do for me, is that the fish can stir up the sand, and keep it clean. When the sand is clean, there will be a less chance of buildups of nitrates, phosphates etc. For the swimming crabs, these guys are scavengers, and will forage for food that is around the aquarium. They usually tend to stay on top of the rocks, and look over the area, but sometimes they swim, which looks stupid, but its awesome. They dont get very big, pretty small crabs that are really hardy aswell. For the viviparous blennies, these guys are actually livebearers, so they will give birth to live fry, and they're rather easy to keep. What this will do, is give the tank a really cool feel, so that it feels like the real ocean with breeding and stuff. And these guys are just awesome, they almost look like eel. These fish are a little more active, however they're mostly just like normal blennies that we get for our reefs. So the idea was, that i either got 1 male and 2 females, or 2 males and 3 females. What this will do, is decrease the aggression level in the tank, and keep it all in balance. As far as the seaweed goes, its really that easy, to just go on the beach and collect some wild seaweed and seastars and crabs and urchins and stuff. So i might see if i can catch an urchin, a seastar and get lots of seaweed home, aswell as that i might be looking for anemones that thrive around the beach area, so that is kinda awesome. I will keep you guys updated, but here is a picture of a Lemon Sole (Picture taken from wikipedia):


Viviparous blenny (Picture taken from glaucus.org.uk):


As far as the seaweed goes, here are some species i might try out:
Fucus vesiculosus (Picture taken from wikipedia):


Fucus serratus (Picture taken from wikipedia):


Fucus evanescens (Picture taken from biopix.net):


Fucus spiralis (Picture taken from aphotomarine.com):


What do you guys think?

Thanks for reading! I might update this topic to get new ideas for this build in the near future. If you guys got any feedback, please feel free to give me your thoughts or ideas!

 

Bump!

 

Neat, but I would just get smaller species, not to mention they could fight or get very stressed out with such a small territory.

 

I agree. I know you said you would rehome them once they get too large, but you are talking about some species that get much too large for all but the largest home aquariums. There has to be some smaller species you could do.

 

Thanks man. After what i got told out there, it should not be a problem. But i will definitely keep peaceful species, and not aggressive and territorial species. Blennies, sea robins and things like that are not really that territorial, flounder can be, but are usually rather peaceful about it I saw rather small tanks (200 - 250 liters) with many different small species, no problems But thanks for the feedback, i'll definitely take it into consideration.

 

Sadly, no. But remember these fish get very old, so there is no reason to grow them in a big system to start with, when i get them to start with in small sizes close to 5-6 cm. In this size, they wont need alot of swimming room, especially sea robins, flounders and crabs. For the schooling fish and the pollock i totally agree, but i would hear about what they say out there, i might start a 150 gallon instead And dont worry, as i said when they get bigger i can just deliver them to the oceanarium and they'll use it for their show tanks

 

you need a new avatar

 

Oh actually, remember i mentioned Bjørn? He grew a small unhealthy small spotted catshark, that had a really bad hatch from its egg. So he took it home and held in a small 50 gallon tank. Now, its in the oceanarium tank, 7 years old, and the oldest shark they have, and its still thriving

 

Haha, yeah i know

 

I would really like to make a viviparous blenny only system with crabs. Because they're really fun to breed and they're awesome. But gotta keep a sea robin and a flounder too, since they're rather easy to keep, dont grow very fast, and i can get a flounder that is 3cm and a sea robin that is about 4cm. Viviparous blennies that they have out there are like a normal blenny that we buy for our reef, but when they get about 12 years old, thats where they get 50cm, but... you know But i see what you mean man, thanks for the feedback