Swedish fish - behind the scenes rebuilding a public aquarium

[gregkn73]

Hej Stig!

For the large tank I think Carlson surge devices will be impossible due to the volume. We can't room that large water containers anywhere above the water surface. And smaller ones won't give much effect. So I believe we will need stream pumps. If we can afford them..
!

Have you seen the reverse Carlson surge device? In theory it doesn't require the space above tank ,you don't have and also provide flow ,deep into the tank .

 

[Sallstrom]

Have you seen the reverse Carlson surge device? In theory it doesn't require the space above tank ,you don't have and also provide flow ,deep into the tank .

I've seen one in action at a public aquarium in Stockholm. So cool!

 

[gregkn73]

I've seen one in action at a public aquarium in Stockholm. So cool!

I would love to see in action one, especially in a huge tank. Next time take a video . So why don't you consider making one?

 

[Sallstrom]

I would love to see in action one, especially in a huge tank. Next time take a video . So why you don't consider making one?

The problem is the size. For a 5000L tank, absolutely. Then we could build it ourselves, and adjust things easy. But with 400m3, the size of this type of wave maker would be massive. And we are struggling already to find space for skimmers, quarantine, RO tanks etc behind the scenes.
Then there's the force, think of say a 2 m3 reversed Carlson surge device, that's some buoyancy
So compare it with a stream pump that moves say 200000 L/h and are the size of a scuba diving tube.

 

[Sallstrom]

I would definitly use a Carlson surge device. If You tune it in with the lenght resonance of the tank you can easily create a wave of an inch or so. That would garantee some flow in the lower areas in the tank.
And if you have a tank of Reef Flat please use sunlight imitation - 10 000K. The bluer light is in greater deep.
I guess you have seen the Giesemann 1000w leds?

I can't find any 1000W LEDs from Giesemann. Do you have a link?

 

[Brew12]

The problem is the size. For a 5000L tank, absolutely. Then we could build it ourselves, and adjust things easy. But with 400m3, the size of this type of wave maker would be massive. And we are struggling already to find space for skimmers, quarantine, RO tanks etc behind the scenes.
Then there's the force, think of say a 2 m3 reversed Carlson surge device, that's some buoyancy
So compare it with a stream pump that moves say 200000 L/h and are the size of a scuba diving tube.

Have you considered trying to do it with a closed loop system establishing alternating flows? Draw a suction from multiple spots along one side and discharge into multiple spots on the opposite side. Create a mirror image of it for flow going the other direction. That way the pumps wouldn't be in the display and you could get good gyre flow alternating directions. You could ramp one up while the other was ramping down to create moving random flow.

And thank you again, that was very kind of you!

 

[Sallstrom]

Have you considered trying to do it with a closed loop system establishing alternating flows? Draw a suction from multiple spots along one side and discharge into multiple spots on the opposite side. Create a mirror image of it for flow going the other direction. That way the pumps wouldn't be in the display and you could get good gyre flow alternating directions. You could ramp one up while the other was ramping down to create moving random flow.

And thank you again, that was very kind of you!

I agree on that it would be easy to hide pipes and outlets amongst the rocks and corals. But then it comes to the pumps. There must be some big pumps to get the water moving.. The pipes from the returpumps/sump will go into the tank. That will be up to 400m3/h I hope.

I tried to get laminar flow in a 700L propagation tank a couple of years ago. First I tried and wasn't happy with the result, then I calculated how much water I needed to move from one end to the other to get 10cm/second flow. I don't remember the numbers now, but I gave up after getting those numbers ;Wideyed Maybe someone could do a formula to calculate laminar flow?

I must sound really old and boring now, just shoting down all ideas that coming on flow. Sorry for that!
It might be that we bought a Ocean Motion 6 years ago, with 8 outlets. I glued all those pipes. And the results where not great. The Ocean Motion worked, just that the pump was to small to get any speed on the water/pipes where to wide and somewhere it sucked in air..
After that we bought the largest Tunze Masterstream. It moves about 150000L/h and cost about the same as the poolpump, pipes and the ocean motion

I got one idea from a friend. It's to put in a couple of pipes from close to the bottom up the close to the overflow. And to use them as airlifts if the water doesn't mix as well as we want and to get detritus up from the bottom layer. But it's still just an idea.

I will do a quick sketch, I think it'll be easier to understand the proportions then
Edit - The sketch comes tomorrow. Need my work computer..

 

[Lasse]

I got one idea from a friend. It's to put in a couple of pipes from close to the bottom up the close to the overflow. And to use them as airlifts if the water doesn't mix as well as we want and to get detritus up from the bottom layer. But it's still just an idea.

Old classic mammut pump. But in order to be effective - it consume a lot of air and in order to work from 4 meters - it need at least 0.4 bar.

Sincerely Lasse

 

[Sallstrom]

Old classic mammut pump. But in order to be effective - it consume a lot of air and in order to work from 4 meters - it need at least 0.4 bar.

Sincerely Lasse

Yes. We will have a compressor for air, both for the tanks and for filling up dive bottles. I thought you knew that

 

[Gregg @ ADP]

Good points!

I think this is something that is discussed too rarely. I really hate seeing ugly stream pump in a otherwise beautiful reef tank. But sure, everyone doesn't have the same taste

Our vision is for the visitors to feel that they are in a underwater station when they go down the stairs to the Aquarium exhibition. And that they look out into the sea, not into an aquarium.
I know this will be impossible to achieve to a 100%, but that's something we will keep in mind when we design the tanks

For the two largest tanks, 60 000L and 400 000L, there will be areas next to the windows that can't be seen from the outside. But the largest one will have two windows, making it a bit harder to find hidden spots for pumps. I will try to draw a sketch of the big reef tank and post here. I appreciate all input I can get.

For the smaller tanks, I think most of them will be in-wall tanks. So as you wrote, by covering the outer parts of the front window you create non-visible space for pumps there.

I tried another way in this existing tank where most of the tank is visible from the front window. There are three Jebao stream pumps behind the rocks, facing the surface. Gives a wave that spreads throughout the tank, not high flow but enough for this tank.

Also remember that people will look all throughout the exhibit...except straight up.

I’m a big fan of external recirc pumps in large tanks because a) you can get a ton of flow with a lot of control over direction, and b) you can hide intakes anywhere (bonus of being able to have them behind main structure which helps eliminate detritus build-up). Then, it’s just a matter of masking outputs.

That’s where the 1st point of people looking everywhere but straight up comes in handy. Black out-puts near the top front simply won’t be seen, especially if the light is angled to avoid hitting that space. You can have a series of 3-4cm outs that only extend a few cm into the water and can be angled however you want them...some @ 20degrees, some at 35, 45, etc.

Then, if you employ something like a motorized ball valve, you can have that flow alternating pretty chaotically. If you have a number of pumps, those can also be on controllers where early and late, maybe half are turned off. Lots of options w/o taking up any space in the display or being visible at all.

 

[Dr. Dendrostein]

Yes. We will have a compressor for air, both for the tanks and for filling up dive bottles. I thought you knew that

Don't forget, might need refrigerated air dryer, if compressor on continously going to add heat and get oiless compressor if possible .

 

[Sallstrom]

Don't forget, might need refrigerated air dryer, if compressor on continously going to add heat and get oiless compressor if possible .

Thanks! I will check with the people drawing the ventilation and water next time we have a meeting.

 

[Brew12]

I agree on that it would be easy to hide pipes and outlets amongst the rocks and corals. But then it comes to the pumps. There must be some big pumps to get the water moving.. The pipes from the returpumps/sump will go into the tank. That will be up to 400m3/h I hope.

I tried to get laminar flow in a 700L propagation tank a couple of years ago. First I tried and wasn't happy with the result, then I calculated how much water I needed to move from one end to the other to get 10cm/second flow. I don't remember the numbers now, but I gave up after getting those numbers ;Wideyed Maybe someone could do a formula to calculate laminar flow?

I would think this would be more efficient than using multiple stream pumps. With almost no elevation change it should be very energy efficient in my mind, but I am not an expert in the field. I work with a mechanical engineer who is very good with fluid dynamics. Do you mind if I have him crunch some numbers on this or see if he has any ideas?

 

[Dr. Dendrostein]

Don't forget, might need refrigerated air dryer, if compressor on continously going to add heat and get oiless compressor if possible .

Your engineer(s) should have it covered, I been around were $10,000 dollar mistake here, few thousand dollar mistake there. Vendors send different equipment, installer mistakes . Just check all base, without getting in their way. What a job you have. Must be nice.

 

[Dr. Dendrostein]

You have alot on your plate, don't mess it up. Only get one try. Heehee

 

[Dr. Dendrostein]

Old classic mammut pump. But in order to be effective - it consume a lot of air and in order to work from 4 meters - it need at least 0.4 bar.

Sincerely Lasse

Hey @Lasse , those pump aren't diaphragm, air driven?

 

[Sallstrom]

I would think this would be more efficient than using multiple stream pumps. With almost no elevation change it should be very energy efficient in my mind, but I am not an expert in the field. I work with a mechanical engineer who is very good with fluid dynamics. Do you mind if I have him crunch some numbers on this or see if he has any ideas?

Sure! The tank will be around 14 x 7,5 meters, and 4 meters deep

I will post a drawing of the tank and the windows tomorrow when I'm at my computer at work.
Or you might figure out where the windows are if you look at this one. The reef tank is the big rectangle at the bottom.

 

[Sallstrom]

Also remember that people will look all throughout the exhibit...except straight up.

I’m a big fan of external recirc pumps in large tanks because a) you can get a ton of flow with a lot of control over direction, and b) you can hide intakes anywhere (bonus of being able to have them behind main structure which helps eliminate detritus build-up). Then, it’s just a matter of masking outputs.

That’s where the 1st point of people looking everywhere but straight up comes in handy. Black out-puts near the top front simply won’t be seen, especially if the light is angled to avoid hitting that space. You can have a series of 3-4cm outs that only extend a few cm into the water and can be angled however you want them...some @ 20degrees, some at 35, 45, etc.

Then, if you employ something like a motorized ball valve, you can have that flow alternating pretty chaotically. If you have a number of pumps, those can also be on controllers where early and late, maybe half are turned off. Lots of options w/o taking up any space in the display or being visible at all.

Good points, all of them. Thank you!
Still some time before we have to decide on these in-tank stuff, but I rather be well prepared when the deadline line is coming. I will take this with me when we start planning for circulation and rock works.

We've started doing this tank in wood, but scaled it down so it's like a 500 litre tank. Just to be able to try out different aqua scapes. Maybe we'll order a model in acrylic and try with water as well.

There has been a lot of meetings on all the large things outside the tanks, like sumps, room for skimmers and sand filters, mixing tanks, pipes to connect tanks in different rooms, RO tanks, and more pipes. So things like rock work, lights, calcium reactors, algae filters and a lot of the smaller stuff are still things we haven't decided completely yet. We have plans, but they might change due to budgets or architects ;Nailbiting

 

[Lasse]

Hey @Lasse , those pump aren't diaphragm, air driven?

"diaphragm" pumps may only be useful to a depth of 1 meter and does not give the flow that you need. If you want a high flow of air down to four meters - you need a compressor or what we call in Swedish "side channel blower".

​

Yes - I do know of the compressor but I do not think it is economical to use a compressor in order to run a couple of "mammut pumps" and this is very important

Don't forget, might need refrigerated air dryer, if compressor on continously going to add heat and get oiless compressor if possible .

I know of experiences that a compressor with the flow that´s is needed and the demand of oil free air is not for free. Compressed air processes are very expensive to run, especially when there is a high purity requirements of the air and a demand of high flow.

Sincerely Lasse

 

[Dr. Dendrostein]

"diaphragm" pumps may only be useful to a depth of 1 meter and does not give the flow that you need. If you want a high flow of air down to four meters - you need a compressor or what we call in Swedish "side channel blower".

​

Yes - I do know of the compressor but I do not think it is economical to use a compressor in order to run a couple of "mammut pumps" and this is very important


I know of experiences that a compressor with the flow that´s is needed and the demand of oil free air is not for free. Compressed air processes are very expensive to run, especially when there is a high purity requirements of the air and a demand of high flow.

Sincerely Lasse

So true, Lasse.
The picture of Mammut pump, it pushes air only?