Trying to understand Kreisels, but they are confusing!

[noperesult]

From what I gather, kreisels are necessary to keep live jellyfish. I hope to build one in the far future, but right now I'm having trouble understanding how kreisels work.

First, if anyone has detailed designs of their kreisels they'd like to share, please do.

I'm looking at the pseudo-kreisel because I think it's easier to build than trying to create a full circular kreisel.

The base design I'll follow is here:
http://i6.photobucket.com/albums/y242/calvin415/1n0130693004.gif

Out of laziness, I'll sometimes use "spraybar" and "inlet" as meaning the same thing. Likewise, "screen mesh" and "outlet" will be the same when talking about water flow.


1) The spraybar points downwards, so the water flow goes clockwise. There is a screen behind this spraybar, where water is supposed to go to your sump through the outflow.

How does the "old water" which is going around in circles get out through the screen mesh? Wouldn't the spraybar push most of the old water around the tank instead of through the screen mesh? Wouldn't this cause all the ammonia, phosphates, etc to just rotate around continuously?

2) To build on (1), isn't it bad to put the inlet near the outlet? Fresh water comes in through the inlet, but then it seems like it gets directly sucked out through the screen mesh with the outlet. Sure, this will create a circular current, but the water in the main tank will still be stale?

Thought experiment: what happens if we place the spraybar (inlet) on the opposite side of the screen mesh (the outlet), so that the flow of water will blow across the top of the tank? Will the jellyfish get caught in the screen mesh?

3) Similar to (2), but slightly different. Does the flow of water rotate in a near perfect oval, along the sides/edges of the tank? If so, how does the water in the center of the tank get rotated out to prevent stale water?

4) Is a 20 gallon long or a 20 gallon tall best suited for a pseudo-kreisel? Does it matter? It seems like both are the same, just the flow rate will be different to account for the horizontal distance vs vertical distance.

5) On bending acrylic at the two bottom corners of the tank, do you glue them on? If so, how do you clean the space underneath the acrylic?

Jellyfish are COOL! Would anyone like to help me out with these confusions?

Thanks!

 

[billsreef]

The constant input of water has to go somewhere, so it goes down the overflow, despite the spray bar. So long as there is adequate turnover, the tank water will be filtered just fine. There will be enough turbulence to prevent a stagnant "core" of bad water in the center, so don't worry about it As for your "thought experiment" on changing the spray location and orientation, yes, it will cause the jellies to sucked into the outlet screen. The pseudo-kriesel came about from a lot of trial and error, and is well established as tried and true. Worth sticking with it as designed In regards to the 20g, I'd stick to a 20 high as it will give you more water column height which is better for pelagic jellies.

 

[noperesult]

The constant input of water has to go somewhere, so it goes down the overflow, despite the spray bar. So long as there is adequate turnover, the tank water will be filtered just fine. There will be enough turbulence to prevent a stagnant "core" of bad water in the center, so don't worry about it As for your "thought experiment" on changing the spray location and orientation, yes, it will cause the jellies to sucked into the outlet screen. The pseudo-kriesel came about from a lot of trial and error, and is well established as tried and true. Worth sticking with it as designed In regards to the 20g, I'd stick to a 20 high as it will give you more water column height which is better for pelagic jellies.

Thanks for the response. How high should the turnover be? At least 88x turnover?

 

[billsreef]

Turnover doesn't need to be very high. Around 6x's should be more than adequate.

 

[slief]

I have a friend who spent years designing, perfecting and patenting his jelliquarium designs. I can tell you from first hand experience that getting it just right is a tedious and expensive task. Flow, outlet and overflow locations and design are critical in insuring that the jellyfish don't bang into walls. The Kreisel is designed to suspend not only the jellyfish but also their food. Too much flow and improper design and the jellies will hit the walls or get sucked to the overflow. That said, how much flow you need varies from one design to the next. You can't just say 6x flow & you will be fine. The shape of the kreisel has a major impact on required flow. For example, a completely round kreisel would need completely different flow than a square one with rounded inserts at the corners like that of your design. If u do try this experiment out, make sure you can control and regulate your flow as you will need to fine tune it to get just right. Otherwise your jellyfish will hit the walls and corners and perish quickly.

Also, a spray bar is a bad idea. If anything sticks out in the kriezel, the jellyfish will hit it and eventually get damaged & die.

I own a 48" Kreisel and have a couple years of jelly fish experience and I can tell you, it's not for the inexperienced nor is it something that you can expect much if any success if you are experimenting. Jellyfish are a pain to keep even with the best setup & feeding is a whole other nightmare!

One last comment. That design you linked to appears to have at least one major design flaw. It's missing corner baffles on the top left. without that, the jellyfish will rise to the surface instead of being suspended in the middle of the water column. As a result, they will get sucked into the overflow screen. Also water should exit through a screen at the top of the tank between the two rounded top corners.

 

[noperesult]

I have a friend who spent years designing, perfecting and patenting his jelliquarium designs. I can tell you from first hand experience that getting it just right is a tedious and expensive task. Flow, outlet and overflow locations and design are critical in insuring that the jellyfish don't bang into walls. The Kreisel is designed to suspend not only the jellyfish but also their food. Too much flow and improper design and the jellies will hit the walls or get sucked to the overflow. That said, how much flow you need varies from one design to the next. You can't just say 6x flow & you will be fine. The shape of the kreisel has a major impact on required flow. For example, a completely round kreisel would need completely different flow than a square one with rounded inserts at the corners like that of your design. If u do try this experiment out, make sure you can control and regulate your flow as you will need to fine tune it to get just right. Otherwise your jellyfish will hit the walls and corners and perish quickly.

Also, a spray bar is a bad idea. If anything sticks out in the kriezel, the jellyfish will hit it and eventually get damaged & die.

I own a 48" Kreisel and have a couple years of jelly fish experience and I can tell you, it's not for the inexperienced nor is it something that you can expect much if any success if you are experimenting. Jellyfish are a pain to keep even with the best setup & feeding is a whole other nightmare!

One last comment. That design you linked to appears to have at least one major design flaw. It's missing corner baffles on the top left. without that, the jellyfish will rise to the surface instead of being suspended in the middle of the water column. As a result, they will get sucked into the overflow screen. Also water should exit through a screen at the top of the tank between the two rounded top corners.

That's a good point about the suspension of food and jellyfish. They shouldn't be floating along the sides of the tank, but rather continuously floating around the center.

I'm not sure I understand why the spraybar is bad. So long as the jellyfish doesn't bump into the spraybar (or the mesh), it would be alright? Here's an example I found: (https://www.youtube.com/watch?v=7FZVGw1d63w). Of course, if the jellyfish is already floating around in the center, then the spraybar wouldn't be a problem in the first place?

 

[noperesult]

This is an interesting tank:
https://www.youtube.com/watch?feature=player_embedded&v=2KTJ8GAWlEs#at=91

It's a square, but it follows somewhat the same idea as all the other kreisels. It's got a spraybar which points downwards towards the mesh, with the jellyfish mostly suspended in the center. The flow seems to work great for small jellyfish, but it looks like the larger ones will outgrowth the tank pretty fast.

 

[slief]

That's a good point about the suspension of food and jellyfish. They shouldn't be floating along the sides of the tank, but rather continuously floating around the center.

I'm not sure I understand why the spraybar is bad. So long as the jellyfish doesn't bump into the spraybar (or the mesh), it would be alright? Here's an example I found: (https://www.youtube.com/watch?v=7FZVGw1d63w). Of course, if the jellyfish is already floating around in the center, then the spraybar wouldn't be a problem in the first place?

That is a perfect example of why a properly built jellyfish tank is not just something you kluge together. Just because you can keep jelly fish in a tank for a short while doesn't make it a well designed system. The ideas is that they actually grow instead of shrink and die over the course of a month or two or 3. There are some good aspects to that design but a some key aspects that make it not so good. The first thing I noticed is that the jellyfish in the link above drag across the top.. That is a major design flaw in that system that will result in jellyfish that don't thrive and instead widdle away. As for that spray bay, notice how the jellyfish spun rather quickly as soon as it got into that flow?? That is another short coming which will contribute to the jellyfish's demise in my opinion. There should be no noticeable change of direction or speed as a result of the return water.

So in short, I think that is a great example of why these tanks are more of a science than most would expect and the above example is a perfect example of a jellyfish tank that has some large flaws.

This is an interesting tank:
https://www.youtube.com/watch?feature=player_embedded&v=2KTJ8GAWlEs#at=91

It's a square, but it follows somewhat the same idea as all the other kreisels. It's got a spraybar which points downwards towards the mesh, with the jellyfish mostly suspended in the center. The flow seems to work great for small jellyfish, but it looks like the larger ones will outgrowth the tank pretty fast.

That is one of Nancy Sowinski's holding systems. She spent many many years and tens of thousands of dollars developing her tanks and her jellyfish diet. That is one of her short term holding tanks and not one of her long term kreisels. She was originally developing that design as a lesser expensive jellyfish tank but if I am not mistaken she abandoned that design a couple years ago. Again, it is not the ideal design for a long term jellyfish tank designed to grow out jellyfish. Also, neither of the two designs would be really suitable for Sea Nettles as they have really long tentacles which will completely encircle the tank and tangle with any other jelly's in the tank. I've tried sea nettles before and they are a nightmare and my tank is a 48" kreisel. The only jelly's in my opinion that are suited to smaller tanks like mine are the moons and smaller jelly's like the blue blubbers.

I will add one more thing to this.. Think of it this way, if you crumble up a piece of toilet paper and place it into either of those tanks but especially the first one you linked to, what will happen to the toilet paper after it's placed into the tank?? In a well designed kreisel, the paper should circle the tank for days on end just like a jellyfish and not come apart. In the first tank you linked to, it will certainly tear into pieces in short order which is a great indicator of the longer term effects on a jellyfish. If you move forward with your endeavor, I suggest you invest in several rolls of toilet paper as your going to spend a lot of time and money experimenting with your design, flow, plumbing, return and overflow locations and I can assure you in the end, you will have far greater success purchasing a well designed kreisel such as those from Jelliquarium as opposed to building your own. Especially if you have to purchase jellyfish which are not cheap, you are not going to want to experiment on those and have to replace them every month or two because they die.