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Introduction of BjornD

Posted: 02 Feb 2016, 08:34
by bjornd
Hi, my name is Bjorn, 40 years old working as an Systems Administrator and just like most of you i’m a koi enthusiast.
I’ll live in Heerlen, the netherlands. I’m one of the many volunteers during the holland Koi show in Arcen.
One of my hobby's is keeping koi of course, but i'm member of a club which trains K9 as police dogs.

I started with koi about 13 years ago, in a very small pond (2500 Liters), after i moved, i created a bigger rectangular pond which contained 24000 Liters of water. This pond was filtered by a small but very efficient DIY 3-chamber filter (Static Bed / Moving Bed / Japanese Matting).







My old filtration 3*330Liter Polyester containers (Static Bed / Moving Bed / Japanese Matting).

After a year i decided to create a small plant filter, after the build my pond contained 30000 Liter.



a year later the pond was expanded again to its later size. at that point i changed the system, in a way so that airlift could be used.

A see through to the 2nd upgrade

2 years ago i decided to create a 2nd filterunit. This filterunis is being build in concrete and a Polyester finish.



the Collector which houses the airlift

A working Crielsieve.


My pond consists of 40000 Liter of water, and will be kept clean by (when i’ve done) 2 filters.
3 bottom drains, 1 skimmer, very small plant filter
1st filter: 2 chambers
• Criel sieve
• Moving Bed
• Airlift
2nd filter: 3 chambers
• Criel sieve
• Moving Bed
• Japanese Matting
• Airlift

My pond runs on 2 airlifts and comsumes only 100 watt in total.
At the moment i’ll have 12 koi swimming around

Re: Introduction of BjornD

Posted: 11 Apr 2016, 13:10
by spirulina
Thank you Bjorn for sharing all this with us. The growth in size of your Koi ponds is impressive.

I had two questionsl

1. Would you please share with us how you fashioned your air injection at the bottom of your air-lifts.

2. Would you be familiar with Seacalcs app for designing air-lifts: ..." onclick=";return false;



Re: Introduction of BjornD

Posted: 02 May 2016, 12:28
by bjornd
Hi Spirulina,

Sorry that my reaction took a while, but my work took a lot of time.

my air injection of most airlifts i build is a 20mm PVC tube, when i use heavier pumps (> 60 Liter/min), then the size will increase to 25mm with a max. of 32mm.

I saw the app, but need to install it, i never used it before.
I hope it knows the metric system as well

Re: Introduction of BjornD

Posted: 02 May 2016, 22:36
by bjornd
I've played a little with the app.
what i found strange, is the size of the airholes and the number of them.

the app needs more variables, e.g. hole diameter
but this is a start, i try to contact the developer.

Re: Introduction of BjornD

Posted: 09 May 2016, 08:18
by bjornd
I,ve contacted the developer, his reaction about my questions are.

They use the air to decrease the size of the debris. so the amount of holes and the size of it, are not important for his line of duty.
but a very important thing, following his idea is the fact to drill the holes in a 45 degree angle.
PVC is a soft material, but the drills in our used size are very brittle. but nevertheless when i've got time, i'm gonna test.



Re: Introduction of BjornD

Posted: 10 May 2016, 14:20
by Frank
45 degree ist exciting...


Re: Introduction of BjornD

Posted: 22 May 2016, 12:02
by bjornd
I updated my first post with some pictures of my pond and filtration.

This is not how it looks like now, because it's a work in process at the moment.

Re: Introduction of BjornD

Posted: 30 Mar 2018, 18:42
by Dave Wraxall
Hey Bjorn,
I've just been watching you on Aquatechnobel. I was wondering if I could ask a couple of questions, please?

I'm originally from England and was a serious koi keeper but have lived in Ontario Canada for the last 30 years, where koi keeping is almost non-existent, so being creative is the order of the day!

I am in the planning stages of building a koi pond which I anticipate may be around 10,000 gallons or 45,000 litres. I'm planning on using an RDF Which runs into a K1 static bed and then a K1 moving bed. I have been toying with a Vortex filter up front, to remove the majority of solids but feel that the automated nature of the RDF may make that redundant and less work! I plan on having a fairly heavy fish load, ultimately (Tosai and Nisai which I wish to grow to 80 cm of bigger, over time), so I want a system that will allow that.

I was going to use a water pump until I saw the Airlift concept, which I am very impressed with. I am just trying to understand how I may incorporate it into my design. I really would like to have a waterfall. The airlift designs I have seen so far, have the returns below water level, going directly back into the pond. I have also seen where an airlift will easily pump the water vertically 5m or more.

I am wondering if I can do a hybrid of the two? Could i run a horizontal 4" pipe, underground from the airlift reservoir, for say 15 m, which would be at the end of my filter chain, to the location of the water and then run the pipe vertically for perhaps a meter above water level and add an elbow, so that the water runs into my waterfall to return to the pond?

The second option I think may work, is to have the airlift reservoir at the waterfall location and supply the water through a 4 inch pip, run underground, perhaps 30-40 cms below water level, from the final chamber in the filter chain. Theoretically, I think both could work, although I have a little less confidence in option 1. I was wondering if you could perhaps give me your thoughts on this?

Also, do I need to be concerned about water flowing into the airpump, if it is below water level and turned off? Do I need to fit a non-return valve or do I just need to make sure that the airpump air pipe is well above water level?



Re: Introduction of BjornD

Posted: 08 Apr 2018, 14:12
by Pssymon
Hello Dave, I think Bjorn is not active on the forum anymore. He is mostly active on the Dutch/Belgian forum. I will ask him if he can reply to your questions.

Re: Introduction of BjornD

Posted: 09 Apr 2018, 05:04
by bjornd
Hi Dave,

Sorry for the late reaction, because of my work, i'm not as active as before.
i will look into it.

Do you have a topic where you can put your plan with a drawing.

Airlift works best in gravity. Everything on the same level. If you want to have an waterfall then its best to use a pump for this and the airlift as a return to your pond.

In that way you have an hybrid system.

Kind regards


Re: Introduction of BjornD

Posted: 05 May 2018, 01:54
by Dave Wraxall
Thanks Bjorn,
I've given it more thought since I wrote my post and what you've said confirms what I was thinking.