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Water Jug Kreisel Tank

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6.45 am my phone rings. I look over and see that the caller ID says that my workplace is calling me. Expecting some sort of "official" business, I take a deep breath and putting on the most "awake" voice I can muster, I answer the phone. It's my co-worker who gets to work at 6.30am and leaves at 3.30pm (we normally work from 8am - 5 pm).

Voice : Hey you got to get down here man.... !
Me : What happened? Did something happen with the job?(referring to the work work).
Voice : Uh.... nope... not exactly.....
Me : What?!!
Voice: I think it's your seahorses... There's like a big black cloud in your seahorse tank. (I keep my 55 gal seahorse tank at the office).
Me : Huh?
Voice : I think it's a big cloud of babies!!!
Me : Oh .... #*$%!

And that's when i realized how terribly unprepared I was for the sudden spawn. I got my butt out of bed and down to the office where my co-workers were happily scooping up the little ponies with little paper coffee cups. The ponies were temporary housed in a 5 gal with a sponge filter and an airstone, but almost all of them congregated at the surface, gulped air and became "floaters". And then i heard of this little contraption called a Kreisel system.

In short, its a tank designed to circulate water in such a way where it keeps its inhabitants suspended in the water column, preventing them from being trapped on the water's surface.

My hunt to "buy" a ready made kreisel really produced nothing. No way was i going to fork out $1,000 to buy a professionally made one. So.... I built my own.....

Please read through the ENTIRE article before using these plans to build your kreisel tank as i leave a lot of space for your own customization. My design is no way near perfect, in fact it has lots of room for improvement. So read the article, tailor it to suit your own purposes and use it as a rough guideline to build your own system.

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  • one 5 gallon jug. (The ones that are perfectly cylindrical and without handles).
  • one 10 gallon tank (Or any small spare tank up to 20L that you have lying around).
  • Something to cut up the 5 gal jug. (Dremel rotary tool, or hacksaw, or reciprocating saw or worst comes to worst, a strong pair of scissors.
  • Clear Silicone
  • Cloth mesh (mesh size depends on what you are housing).

Here you see the 5 gal water jug I used and my choice of tanks (10 gal in this case):

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Step 1: I measure out the width of the space between the "long" side walls of the 10 gal. Then i cut the top and bottom off the water jug to make a cylinder that will fit snuggly between the walls of the 10 gal.


Step 2: Next I cut a little section out of the side of the cylinder. This will eventually become the top of the the main kreisel compartment of the tank. This cutout will later greatly help us to to "twist" the water jug into the 10 gal, especially if you have a tank with a plastic or wood trim on top, which usually make the top of the tank smaller than the actual distance between the panes of glass.


Step 3: Then I cut out a small "window" on the side of the cylinder next to the gap which I cut out earlier.


Step 4: Test fit. This might take a bit of finesse (and some brute force) if you have trim at the top of the tank (like the black trim that i have here in the picture. Experiment a little bit and if you have measured the length correctly (step 1), you should eventually get the jug into the tank.

The gap should be facing upwards.


Step 5: Cut out a small piece of mesh and silicone the whole thing to the little "window" which we cutout earlier. Make sure that you pull the mesh as taut as you can across the window so that we get a nice smooth surface. I recommend attaching the mesh on the outside of the water jug because we want to keep the inside of the jug as smooth as possible.

I guess i could have done it a little better... the siliconeing job looks pretty shabby but take your time and make it as pretty as you want.


Step 6: I don't have pics of this, but when you are happy with the entire setup, go ahead an position the jug in the location that you want within the tank and then silicone the sides of the jug to the walls of the tank to form a watertight seal all around.


Step 7: Test run!

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Here's a vid of this Kreisel tank at work. Because I used a relatively small 10 gal tank to build this prototype, in order to keep up water quality and grow out more pods for the ponies, I attached a "Hang on Back" refugium to the back of the tank. If you use a longer tank (like a 20L or 30L), you can do a built in fuge in the area outside of the main kreisel jug.


Here's another vid from later on and the ponies are bigger. I put in a little cardboard cutout in front of the tank because i noticed that the ponies were attracted to the ceiling light in front of the tank and were gathering on the surface in the front. To prevent "floaters", the cardboard is there to block out the ceiling light.

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My original tank has been running for about 2 months now and has played host to 3 reidi spawns, here's a list of possible improvements which I will try to build into my next DIY kreisel.

  • Mesh clogs easily and is hard to clean (i have been using a toothbrush to clean it daily). Increasing mesh size is not an option for me because the baby ponies can easily escape. Next time i'll try to design a removable screen or perhaps even just sticking a filter sponge into the gap.
  • Single inlet (from the HOB fuge in this case) in the center of the kreisel cause fast flowing water in the center span of the kreisel but very little flow at the ends right next to the glass. Hence i tend to get "floaters" right next to the glass. Next time round i'll put in a spraybar across the entire span of the kreisel to create an even water flow.
  • Inlet position. In the videos above, you will notice that i place the inlets on the "back end" of the circular flow. I. e close to the side of the cylinder where the water dips back down into the tank from the surface. This causes an area of low flow on the "front end" where the water flows up to the surface from the tank. Ponies like to gather in this area of low flow on the surface, thereby increasing the chance of "floaters". Next time i will move the inlet to the "front end" and position the jet to "blow" horizontally across the surface of the water. This surface turbulence should prevent the ponies from congregating at the surface.
  • Tank Size. The 10 gal is a nice start, but it was just too small to maintain the water quality easily. Expecially with thrice daily feedings. This necessisated the addition of a HOB fuge. I believe if i were to use a 20L, there would be more space to do a built in fuge add a skimmer etc. Plus the greater water volume will help in making the water parameters more stable.
  • Kreisel Color. Yes COLOR!!! Expecially for baby seahorses. I have been noticing that the ponies are attracted to light. Even with the current in the tank, i notice that the entire herd of ponies migrate all around the tank depending on the time of the day. I noticed that they were moving around according to the direction of the sunlight shinging through the window! Next time i will paint the water jug black before installation. This should also cut down on the algae growth within the jug.

Here's the latest incarnation & inhabitants of the 10 gal kreisel that i built. This spawn was HUGE! As you can see, I added an inlet at the "front" end of the flow to push the water across the surface. Also, I replaced the mesh screen with a removable sponge that I bought from the store. Seems to work fine for now.

I strongly suggest to watch the below video in High Quality. Click on the red HQ button on the bottom right of the video.

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On the urging of my friends, I started this website by putting together the original (and quite successful) B. Macrostoma pages. Since then it has grown to include much more aquarium related information. All this time I've provided all this info and lots of free e-mail support to anyone who needed help. The advertising on this page helps out a little to offset the cost of webhosting. So if you see something that you may be interested in listed within the GoogleAds banners, then please don't hesitate to check it out.
I thank you all for your great interest in my articles and I hope to keep hearing from you guys, even if it is just dropping me a note to say hi. God Bless!

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