Airlift update: Koi pond running just on air

[estanque_koi]

I received a private message from a member of this forum. He was asking for updated info on the airlift system and pond that I described sometime ago in this Forum (http://www.koiquest.co.uk/forum/viewtop ... f=3&t=5412" onclick="window.open(this.href);return false;).
I believe it could be worthwhile to post an update.
The pond belongs to my friend Jose Antonio Frutos, who has been the President of the spanish koi keeper's society (A.E.K., http://www.elkoi.es" onclick="window.open(this.href);return false;) until last june 2010. Having visited him each summer during the last few years, I have closely followed the evolution of his filtration system, pond and koi.
This pond has been successfully runing for 2'5 years now just on air, using 3 airlifts and 125 watts during spring and summer.
Following the link below you can wacht a video of his pond and Koi, but the filtration system is not featured in this video - I'm sorry.

http://vimeo.com/9142302" onclick="window.open(this.href);return false;

Here are the main features of the pond:
pond design- formal style, partially raised aboveground
shape- rectangular, with 2 large windows of 2 x 0.60 m each in one side
build- home made by his owner, blocks rendered and fiberglassed, finished with topcoat
dimensions- 6 x 3 m
water depth- ranging from 1.4 to 1.9 m
pond volume- 30 ton (30,000 liters)
2 aerated BD, powered by a Hailea W30 air pump (25 w, 30 liters/min)
2 small homemade skimmers
filtration system- based on Kaldnes K1, roughly 20,000 liters/h of water is moved by 3 airlifts powered by a Resun 100 w air pump (150 liters/min)
a 15 w submersible UV is used only during one montgh in the spring, after that is unnecesary
Koi population- 29 fish ranging from aprox. 45 cm to 70 cm (Sakai FF, Momotaro, Shinoda, Isa, Omosako, ...)
feeding- at least 700 g per day during the summer

Filtration system
two homemade filters of 700 and 500 liters of capacity respectivelly, using a total of 600 liters of Kaldnes K1 as filtration media. A water flow of 20,000 liters/hour is achieved with 3 airlift pipes (110 mm) 1 m depth powered by a dedicated Resun air pump 110 w (150 liters/min). In order to reduce friction and achieve a higher efficiency, 16 mm flexible tube is used to conduct the air to each airlift. In winer the Resun pump is replaced by a Secoh 40, so less energy consumption.
Water inflow- 2 airlift pipes (110 mm) pumping water from the BDs, plus 1 airlift pipe (110 mm) pumping water from the 2 skimmers.
In the main filter, the 2 airlifts pipes pumping water from the 2 BDs come vertically into the 1st mechanical filter chamber, having their upper extremes set at the same height than the pond water level. Air is injected in each airlift at 1 m depth via an small PVC closed tube with many drilled holes 1 mm size. When the air pump is on lots of water come out reaching 5 cm high above the pond water level. When the air pump is automatically switched off by a modified timer (see below), the pond water ceases to move into the filter, even if it is drained for cleaning purposes.
Water exit the mechanical filtration chamber (static K1) of the main filter by 4 x 110 mm pipes placed in one side, and protected with a sort of wide cage made of 0.9 x 0.9 cm mesh preventing the exit of K1 towards the next bio chamber and facilitating the water flow.
In the next, biological chamber, there is a metacrilate moving plate of 50 x 20 cm. When the airlifts are pumping water this plate is partially open leaving the water flow in, but whe the airlifts are off for cleaning the plate closes by his own weight preventing the water flowing back by gravity to the mechanical chamber when this is drained for cleaning.
Water moves across the filtration media and through a wide pass of 50 cm wide and 20 cm depth back into the pond. This pass is protected by a mesh to prevent K1 moving in to the pond.
The second filter has got just one chamber and is fed by the 110 mm airlift that pumps water from the skimmers. This third airlift is also powered by the same Resun air pump, and basically works as described above.

Automatic cleaning
the system has been working successfully for the last two years, 2'5 years in fact, providing excelent water quality and no health issues at all. Best of all, the system has been tunned to self-cleaning automatically.
This is achieved by using a modified, inexpensive timer. The unit was internally manipulated to take advantage of a third internal connector that normally goes unused. This allows to use the timer to simultaneously switch on and off devices plugged in the second and third internal connectors of the timer, and viceversa.
When the main device plugged in the main connector of the timer (i.e. the water pump feeding the airlifts) is switched on, the water is flowing from the pond through the filtration system and back to the pond in a normal filtration mode. Two other devices (a secondary air pump and a small water pump, both used for cleaning the filter) that are plugged into the third connector of the timer, are switched off.
And viceversa, at the programmed cleaning time the main air pump feeding the airlifts is switched off, the secondary air pump and the small water pump are switched on for 15 min. The secondary air pump moves and churn the K1 for cleaning purposes, the small water pump is submerged in the first chamber and pumps dirty water out of the filter. This cleaning process takes time automatically once a day during spring and summer. Besides, the chambers are manually drained by bottom exit valves at convenience. Usually once a month or every 15 days while heavy feeding is taking place.
keep the filtration system runing.
I'm sorry for this very long post, hope it can be interesting for you. All the best,

Diego
A.E.K.
Asociacion espanola del Koi
Spanish Koi Keeper's Society
http://www.elkoi.es" onclick="window.open(this.href);return false;

[fair1535]

Hi Diego
Fascinating stuff, great video of fish, any chance of some pics of the system, will be starting my new build soon and will be using airlift, so more info the better. Regards. Steve

[okome]

Thank you Diego.
The Airlift has a huge future in the Koi.world, as it already has in the commercial fishindustry. Every new and old project help people all around the world to build there own project. I´m still waiting for the blue-print, where you can put your own parameters and get the ultimate system for "your" pond. That will be the day. Thanks.
Elias

[ajb]

Very interesting, and for me in particular the bit about the automatic filter cleaning. I am in the process of setting something similar up myself and it's good to hear that someone else has achieved it successfully.

[okome]

Hallo Diego.
I´m really curiuos about the line "-roughly 20,000 liters/h of water is moved by 3 airlifts powered by a Resun 100 w air pump (150 liters/min)" HOW? Dia of the pipes? 110mm or 2" as in the test from the original artikel? Lenght of the pipes? How are the pipes buillt? Outside the pond or in the pond? At what depht is the air introduced? How is it introduced? 9mm airhoses and no airstones? Airlines inside the pipes or outside? Sorry Diego for all the questions, but I feel that I´ve the opportunity to get some answers to a lot of trail and errors with my own airlift.
Elias

[estanque_koi]

my friend invested many hours testing different airlift design and sizes, and different ways to modify his original filtration system (Ultrasieve II, Sequence pump, aerated K1 biofilter) to make it work by airlifts.
Seaking for simplicity and efficiency, but constrained by his pond features, he finally came out to his current setup described in this post. Regretably I haven't got pictures of the filtration system. I'm attaching a drawing showing the approximate design.
As I said, there are just 3 airlift each one of 110 mm diameter. He realized that these can deliver a high water flow rate providing that they are installed to deliver water at the same pond water level (whithout having to rise the water). This detail is very important to achieve a high flow rate.
Remember that he's got just three 110 mm pipes coming from the pond to the filtration system (2 from the BDs, 1 from the 2 skimmers). He modified the end of these 3 pipes to make them working as airlifts. Basically what he did was to glue a new vertical section at the end of each 110 mm pipe, There are no airstones inside the airlift, but a small closed pipe with multiple holes drilled to let the air flow easily into the airlift at 1 meter depth. The airlifts come into the filters vertically through their bottoms, and have their upper extremes at the same pond water level.
In order to achieve a high water flow rate through the filtration system, is is also extremely important to have very wide water transfer ports between filter chambers and back to the pond. Everything to keep resistance against water flow and water head to the minimum.
Hope this can be helpful, Elias.

[okome]

I´m very happy now. This is the information I was looking for right from the start. But, as they say, those who want to know a little bit more, - "Basically what he did was to glue a new vertical section at the end of each 110 mm pipe, There are no airstones inside the airlift, but a small closed pipe with multiple holes drilled to let the air flow easily into the airlift at 1 meter depth". You are so god with drawings, could you give me a small one how the vertical section looks like and how the small closed pipe with small holes is fitted into the system? What size the holes(It´s very critical im my system)? How many? What kind of manifold is Mr Frutos using? Again Diego, sorry for all the questions, but I´m working with the blue-prints for my next pond, The Dream Pond, 100m3, small indoor pond inside a wintergarden(ice cold in Sweden during winter), big pond outside with a connection between, airlifts with big pipes inside the moving bed filter(or maybe the airlift is a big moving bed filter. We`ll se) and easy maintenance. So right now I´m happy for all the answers I can get.
Elias

[markchip]

Hi Diego,

Just to echo the last post by Okome, I'm building a (15,000l) pond next year and want to use an airlift return to the pond. I will probably use 4 110mm airlift pipes of about 1.3m length. The air entry will be near the bottom of each pipe using 15/16mm pipe and drilling many 1mm holes - how far into the airlift (110mm) pipe does the air (16mm) pipe go?

My reasoning for using 4 110mm pipes in the airlift is that it will be much easier to balance air flow just by tee-ing the air supply pipe and then teeing each again (so 4 air supply pipes) even from a single pump.

As I aim to get 20,000l/h flow or more (I'm using an anoxic filter set up) I will ensure that the all transfer ports will be as large as possible. My next question is: - should I use one 100w/150l/min air pump or two of a lower power so that if one failed I would still keep some flow going through the filter? Naturally 1 pump would be cheaper but 2 gives more security. Are 150l/min pumps more than I will actually need in fact?

Thanks, Mark

[okome]

Mark.
Security, 2 is better then 1. I´m trying to make a new manifold to my 40w pump and 7 airlifts.. The 90w pump will be divided between the 7 airlifts, BD and the bio(japmats). 2 manifolds to two pumps. 110mm or 75mm is the way to go. 14 2" as I have, are too difficult to balance. No Ts or fancy things at the top. Just cut the pipe at pondlevel, or even below. Probably you´ve been here:
http://www.freshwaterstingray.nl" onclick="window.open(this.href);return false;
but if you haven´t, it´s a great construction. There you have some huge airlifts in "the Mega tank"
Elias

[B.Scott]

Very nice pond Diego. Those windows are massive. He has alot of guts to install such huge windows. I would be more than a little frightend, but your friend has done a great job!

B.Scott