Introduction to the Crielsieve, a revolutionary pre-filter!

[Pssymon]

While we focus on the development of Airlift technology, we are looking to improve every aspect of running a pond succesfully, with as little maintenance as possible.
The filter is a very important aspect of any stocked pond. Keeping it clean can be quite a challenge.

Most of us are familiar with the usual pre-filter solutions, such as brushes and matting.
These require frequent cleaning, and cleaning can be a big hassle depending on the size of your filter.
There is an alternative; the drum filter.

The drum filter is unbeatable in terms of performance and convenience, since it can clean itself.
The downside is that a drum filter will cost you thousands of euros.

The Crielsieve system can fill the void between the simple brushes or mats and an expensive drum, and make the brushes obsolete, while reducing your maintenance intervals and making your life a whole lot easier.

What is the Crielsieve and how does it work?

The Crielsieve was designed by Marc a couple of years ago. In regular sieve systems waste is caught on the sieve, letting water pass through downward.
The Crielsieve functions differently altogether.
The sieve element is placed in a frame at an angle, similar to conventional systems.
It's placed upside down though, which means the openings (slits) in the sieve face the other way.
This setup is placed in your first filter chamber where the pond water enters.
The sieve seals and forms a barrier between the incoming water and the feedthrough to the next chamber, however, this setup would clog in about an hour.
The solution here, as with Airlift, is air.

We use a perforated tube at the bottom of the sieve which is connected to an air pump. This will force small bubbles through the holes, which meet the surface of the sieve.
The bubbles will travel upwards, hugging the surface of the sieve because they are too big to pass through. This proces continuously cleans the entire surface of the sieve, greatly extending the time period the sieve can function without cleaning.

By regulating the airflow an Airlift and a Crielsieve can both be run on one air pump.

In part two of the 'Airlift: How to build' video Marc shows the Crielsieve working in his own pond.
This can be viewed here: (Video automatically starts at 6:04)

https://www.youtube.com/watch?v=q6Lywn8fAgc&t=6m4s

[Rich Palmisano]

I would like to bring awareness to a filtration method that I have not seen discussed on the page: Bubble Bead Filtration.

Basically this is a bead media filter, pneumatically run with an air pump that does solids filtration as well as bio-filtration all in one. I have seen some of the builds, with filters, sieves, drum filters etc. I see this as a very costly and most importantly, I highly hands on maintenance operation. Bubble Bead filter maintenance is minimal. Backwash solids on a regular interval, depending on size of pond, stocking, etc. Done.

Standard filtration of solids is accomplished by a floating bio-media bead, that removes solids down to the 50 micron level. Bio-filtration is amazing as well. Ammonia and Nitrite is converted to Nitrate at a high level once the system is properly cycled.

The drawback of course is cost. A unit that will filter a 4000 gallon pond (9000 liters) will cost approximately $2000 US. Larger units might be more costly. But the advantage is that you get two for one. Bio and Mechanical Filtration in one system that is a maintenance dream, not a nightmare.

Not sure how available these are in Europe, but they are gaining popularity in the US among aquaculture and aquaponic commercial and residential users because of the efficiency of filtration, the water quality and the ease of maintenance.

[Pssymon]

Hey Rich,

Thank you for your comment.
Are you talking about the small perfect round bead filters or do you mean filter media such as K2? By that I mean the plastic wheel shaped filter media which are designed to maximise surface area for each piece.

I have a lot to say about this but I will await your comment to be sure what you are talking about.

[Rich Palmisano]

Hello,

The filters I am talking about are specifically from AST Filters. They are bubble bead filters, meaning they run using air to backwash the media and discharge sludge. Some models discharge sludge automatically, all models backwash automatically using air as the trigger. Than can be run on air lift as well, with requirement for specific flow rates.

The media they use is a floating "canoe" shaped bead, larger than a grain of rice. Don't really know for sure how large, but the media is enhanced with 'voids' for bacteria growth. The beads also provide mechanical filtration. The loading that these filters can handle, fish and feed, is just astounding to me and they deliver mechanical filtration down t0 the 50 micron level with one pass and lower to the 25 micron with further passes through the media.

The smooth round beads are not effective in either mechanical or biological filtration for the following reasons. Mechanically, they tend to do something called "chanelization" which means when they get loaded with solids, they form channels for the passage of water...and solids. They also are not ideal for bacteriological growth.

Kandis K2 is an exceptional biological media, however that's all it is. It doesn't do a great job of mechanical filtration.

I am STRONGLY considering purchasing a model that will handle 2000 gallons with a fish load of 225 at full grow out. This will require a lot of feed, for plant production, yet water quality can be maintained with TAN levels well below 1mg/L and aproaching .1mg/L.

Add UV sterilization and you pretty much have water quality suitable for any aquatic life.


Footnote: I am not selling this product nor endorsing it. From my research, the system seems to best suits my needs, but also would fit the needs of Koi Ponders as well.

[Pssymon]

Hi Rich, apologies for my late reply.

I'll reply to specific parts of your post to avoid confusion.

Hello,

The filters I am talking about are specifically from AST Filters. They are bubble bead filters, meaning they run using air to backwash the media and discharge sludge. Some models discharge sludge automatically, all models backwash automatically using air as the trigger. Than can be run on air lift as well, with requirement for specific flow rates.

Sounds interesting. I have not heard of these specific filters before. What you're describing sounds like an advanced type of moving bed filter, but with smaller media than usual. Do you have some examples of these filters running on Airlift?

The media they use is a floating "canoe" shaped bead, larger than a grain of rice. Don't really know for sure how large, but the media is enhanced with 'voids' for bacteria growth. The beads also provide mechanical filtration.
Floating media with maximum surface area is something I'm familiar with. What you're describing sounds smaller than what I've seen though.
The loading that these filters can handle, fish and feed, is just astounding to me and they deliver mechanical filtration down t0 the 50 micron level with one pass and lower to the 25 micron with further passes through the media.

I have heard different opinions on moving bed filters (which this seems to be), but many people swear by them. In theory they are very effective due to the fact that the bacteria on the media are constantly aerated, and are able to work more efficiently because of that. I wonder how the mechanical filtration is achieved? Since the media is constantly moving.

The smooth round beads are not effective in either mechanical or biological filtration for the following reasons. Mechanically, they tend to do something called "chanelization" which means when they get loaded with solids, they form channels for the passage of water...and solids. They also are not ideal for bacteriological growth.
I haven't used these filters myself, but I do know there are some pretty advanced systems using round beads. I think these can work but they are probably not the most effective way of filtering. I agree 100% that there are much better types of media for optimal growth of bacteria.

Kandis K2 is an exceptional biological media, however that's all it is. It doesn't do a great job of mechanical filtration.

I am STRONGLY considering purchasing a model that will handle 2000 gallons with a fish load of 225 at full grow out. This will require a lot of feed, for plant production, yet water quality can be maintained with TAN levels well below 1mg/L and aproaching .1mg/L.

Add UV sterilization and you pretty much have water quality suitable for any aquatic life.

Sounds good! I do think the downside is the cost, as with drum filters. You mention this system costs $2000 and upwards. I do know that systems like this, or proper drum filters will always be quite expensive so they may not be for everyone. The Crielsieve is intended as a cheaper option for those who do not want to invest thousands. I could probably build a sizeable pond running on Airlifts + a Crielsieve for $2000... It all depends on how much you can- or wish to spend.


Footnote: I am not selling this product nor endorsing it. From my research, the system seems to best suits my needs, but also would fit the needs of Koi Ponders as well.
Please feel free to discuss anything you want. Your input is much appreciated, we encourage anyone to discuss any type of pond tech here. Critical thinking is always important.

[Rich Palmisano]

Hello,

The filters I am talking about are specifically from AST Filters. They are bubble bead filters, meaning they run using air to backwash the media and discharge sludge. Some models discharge sludge automatically, all models backwash automatically using air as the trigger. Than can be run on air lift as well, with requirement for specific flow rates.

Sounds interesting. I have not heard of these specific filters before. What you're describing sounds like an advanced type of moving bed filter, but with smaller media than usual. Do you have some examples of these filters running on Airlift?

https://www.youtube.com/embed/Zb0Fr3wqSgE

The above link shows a system running off an air lift. Not AirLift, but obviously the AirLift system can be adapted to this filter. I called and spoke to Paul, the person doing the presentation here, for about an hour about their product, what their claims are, and what it can do for me. They specialize in aqua culture, fish rearing and production, but have units for the hobbyist as well, and ones that suit aquaponics (my bread and butter).

The media they use is a floating "canoe" shaped bead, larger than a grain of rice. Don't really know for sure how large, but the media is enhanced with 'voids' for bacteria growth. The beads also provide mechanical filtration.
Floating media with maximum surface area is something I'm familiar with. What you're describing sounds smaller than what I've seen though.
The loading that these filters can handle, fish and feed, is just astounding to me and they deliver mechanical filtration down t0 the 50 micron level with one pass and lower to the 25 micron with further passes through the media.

I have heard different opinions on moving bed filters (which this seems to be), but many people swear by them. In theory they are very effective due to the fact that the bacteria on the media are constantly aerated, and are able to work more efficiently because of that. I wonder how the mechanical filtration is achieved? Since the media is constantly moving.

These are not a traditional moving bed filter. The moving bed filter is specifically designed for biological filtration, where ammonia and nitrate converting bacteria can converted to Nitrite, a much less harmful chemical in aquaculture. These filters do both operations, biological and mechanical. The beads are compressed at the outlet, they don't move like a traditional moving bed. The compressed bead act as a mechanical filter.

The smooth round beads are not effective in either mechanical or biological filtration for the following reasons. Mechanically, they tend to do something called "chanelization" which means when they get loaded with solids, they form channels for the passage of water...and solids. They also are not ideal for bacteriological growth.


I haven't used these filters myself, but I do know there are some pretty advanced systems using round beads. I think these can work but they are probably not the most effective way of filtering. I agree 100% that there are much better types of media for optimal growth of bacteria.

True, these are advanced systems. I have been researching them for about a year though, and based on that research and the available information from AST, they are EXTREMELY effective at solids removal along with Nitrification of Ammonia and Nitrate.

Kandis K2 is an exceptional biological media, however that's all it is. It doesn't do a great job of mechanical filtration.

I am STRONGLY considering purchasing a model that will handle 2000 gallons with a fish load of 225 at full grow out. This will require a lot of feed, for plant production, yet water quality can be maintained with TAN levels well below 1mg/L and aproaching .1mg/L.

Add UV sterilization and you pretty much have water quality suitable for any aquatic life.

Sounds good! I do think the downside is the cost, as with drum filters. You mention this system costs $2000 and upwards. I do know that systems like this, or proper drum filters will always be quite expensive so they may not be for everyone. The Crielsieve is intended as a cheaper option for those who do not want to invest thousands. I could probably build a sizeable pond running on Airlifts + a Crielsieve for $2000... It all depends on how much you can- or wish to spend.

I agree. The downside for a hobbyist is cost. For larger systems it becomes very expensive, however you have to consider that for the cost of the type of filter I am discussing, you get two filters. You get a mechanical filter capable of filtration down to 10 micron (after successive passes of water through the filter, first pass through clean media is 100-50 micron and then descends as the filter captures solids) and a biological filter that will maintain water quality. Also, maintenance is a backwash. No removal of media, no spraying clogged filter media (i.e. extruded filters, sieves, media) and no messy hands. Just turn a three way valve and flush solids. So comparatively, if you consider that you don't have to build a massive filtration system, it could be cost neutral depending on the size of your pond.


Footnote: I am not selling this product nor endorsing it. From my research, the system seems to best suits my needs, but also would fit the needs of Koi Ponders as well.

Please feel free to discuss anything you want. Your input is much appreciated, we encourage anyone to discuss any type of pond tech here. Critical thinking is always important.

Just bringing options to the forum. This one seems to be a game changer. I am convinced.

[Richard_in_Sydney]

Good day from Oz
Is there any other information on the Crielsieve available?

I am playing around with converting a 50,000 l disused in-ground concrete swimming pool to a fish (not Koi) pond and came across first the Airlift (which went together very easily) and now the crielsieve.
Right now I am just experimenting to learn what different bits go and what impact they have.

I have built some temporary floating planters, some airlifts, some floating skimmer boxes.

Now I want to experiment with filtration.
I have a lot of very fine silt making its way into this pond and am experimenting with ways to remove it.
It is smaller than 300 microns (as it passes through a 300 micron bag easily).

And the crielsieve looks interesting.
Unfortunately for the crielsieve there is much less in the way of documentation that I can find.

Is there some good description available (good enough to build from?)
Thanks

Richard

[Pssymon]

Hi Richard,

I will contact you through PM.
Greetings.

[gerard69550]

Hello everyone,

My name is Gérard, I live in Ronno, a small village in the Rhône at an altitude of 500m in Beaujolais Vert, where my wife and I have guest rooms.
In 2010, I created a 60 m2 pool, approx. 35 to 40 m3, with 3 levels (depth in the center approx. 1m50), whose primary function was the retention of roof rainwater, WITHOUT filtration system. The waterproofing was carried out with an EPDM sheet placed on felt, turned around on the periphery on an Ecobat type recycled PVC border 15 cm high.
Over time I planted a few shrubs around it, and also put aquatic plants in baskets placed on the first landing, and finally a few goldfish. The whole thing behaved well for 9 years, and seemed to have found a balance. The plants have progressed and the goldfish have multiplied.
As you might expect, the water clarity today left something to be desired.
Attached are 2 photos of my pond that I emptied and cleaned this summer.


I haven't built anything yet but, with the videos from AQUATECHNOBEL and those from the AIRLIFT.EU site, I prepared the design of a filtration basin adjacent to the pond to set up a top filtration system :
- principle: in gravity
- masonry pool of approximately 4m3 (4m x 1m x 1m), hidden behind the pond, including:
- an inlet compartment of 4 pipes Ø 110mm coming from 2 bottom bungs and 2 bank skimmers
- a brush compartment (1m x 1m x 1m)
- a Japanese rug compartment (2m x 1m x 1 m)
- a compartment for a UVc Amalgam 105 W
- then propulsion by 2 AirLift Ø 110 mm each placed in a chamber of Ø 250 mm

I was going to finalize this design when, while browsing this forum, I came across the post "Introduction to the Crielsieve" by Mr. Pssymon. This upstream filtration system seems perfectly suited to my project. I find it very innovative.
Is this difficult to implement? Can you help me with the sizing and would it be possible to obtain plans, and also the 300micron grids?
Well done, would this allow the brush compartment to be removed?


I thank you in advance for your support.
Gerard
Translated with the help of Google Translate