I have been getting questions quite regularly about how to incorporate airlifts into an RDF filtration system. My answers have always been long drawn out and sometimes vague (sorry guys ) and mostly I have had to request patience while I get a video that demonstrates all the features I have designed into the system. Well I finally got around to making the video but unfortunately it wasn't the best weather day today.
To start off this system will be featured at the Central Florida Koi Show so anyone that wants hands on needs to bring their booties to Orlando March 9th, 10th & 11th.
Those of you not lucky enough to come to the show are still able to ask your questions in this thread.
The system is currently flowing at 6200 gph and the electrical specs are below...
Supply Voltage at the Killawatt Meter...
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Electrical Usage from Hakko 100L....
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Electrical Usage from Hakko 100L and KC-30 RDF....
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Electrical Usage from Hakko 100L, KC-30 RDF, and 1/2 HP Jet Pump for 8 seconds....
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To further explain the filtration system I will break each component down in detail.
The airlift manifolds are the means in which the water gets circulated through the system. The air pump, in this case a Hakko 100L, compresses air and pumps it into the injection manifold at the bottom of the airlift (Letter B). The injection manifold distributes the bubbles inside the contact chamber of the airlift (Letter C) and greatly reduces density of the water inside the contact chamber. The submergence of the airlift (Letter A) is a point in which the air/water mixture are completely encased by a vertical riser tube. Submergence depth is refered to as the distance between the bottom of the riser tube and the surface of the water that the airlift is connected to. In the video above the submergence depth is 44". That measurement tells us that the water pressure pushing toward the airlift manifold is 44" of water pressure which equates to 1.59 PSI. So the 4" pipe that connects each airlift manifold to the pond has a pressure of 1.59 PSI. When the air bubbles are injected into the contact chamber of the airlift it greatly reduces the density of the water therefore reducing the pressure in the contact chamber. Since the low pressure contact chamber is connected to the high pressure 4" pipe the water begins to push from high pressure to low pressure and the air/water mixture is pushed up the airlift riser tube. The height in which that water mixture will be pushed up to is dependent on the pressure difference between the contact chamber and the pressure in the incoming water pipe. This pressure inequality is the only reason why bubbles rise in water. The air bubble has a lower pressure than the water so the high pressure water pushes the air bubble to the surface. In airlifts you are trying to achieve the highest water pressure in the incoming pipe (your submergence) and the lowest pressure inside the contact chamber, so that you have the greatest possible difference in pressure. The greater the pressure difference the more force that is exerted on the water/air mixture so more water will flow through the airlift.
Dirty Water Collection Chamber and Just-In-Case Filter...
The airlift manifolds pump the dirty water from the pond into a container that is so great it has two names . The first name is the Dirty Water Collection Chamber (DWCC) which is simply an empty container that connects multiple supply lines (Letter A) into vessel that transports the dirty water into the RDF (Letter B). It would be much too difficult to try and connect four 3" airlift riser tubes into a manifold that would vent the air and connect three 4" inlets of the RDF. The DWCC is also a great way to pre-filter the extremely large debris out of the water before it goes into the micron-screened drum. This 1" x 1" divider (Letter C) allows all the small particles to pass right through into the RDF while stopping the large debris like small twigs and large leaves.
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Whenever you notice large debris has collected on the divider just remove the divider from the filter remove the large debris and place it back in the DWCC.
The second name that the filter goes by is the Just-In-Case Filter (JIC). The name pretty much says it all. You only use it in the worse case scenarios. If for some awful reason you experience an electrical power surge from a lightning strike, or even worse if your filter pit floods and the electronics get submerged with water then you will have no way of mechanically cleaning the micro-screen drum. This means you either need to stop the water flow or remove the access port on the drum screen and allow unfiltered water to pass freely through the drum. If you choose the second course of action then you have a backup plan due to the JIC Filter.
You simply insert the custom cut Matala Mats into the DWCC and reduce the total water flow so that the mats provide your mechanical filtration. This allows you to sent clean water into your biological filter and still bypass the micro-screen drum. This by no means is meant to be a long term solution because it will require daily maintenance in cleaning the filter pads but it allows you to keep your biological filter alive and provide some circulation through the pond while you make repairs to the filter. Cleaning the pads is extremely simple. Just stop the water flow, shake each pad individually inside the JIC filter then remove it once it is clean. After all pads are cleaned and removed you simply drain the JIC filter through the 3" drain (Letter D).
The DWCC/JIC Filter also allows you to individually flush out the bottom drain/skimmer pipes of any settled debris. To do this you simply stop the flow of water, drain the DWCC and then remove the airlift riser tube's standpipe inside the DWCC to allow a massive surge of water flow through the line and purge any settled debris. Once the line is clear reinsert the standpipe and the water flow stops. This simple procedure saves you lots of money on 4" cleanouts, valves and plumbing lines that would otherwise be needed on each bottom drain/skimmer line.
Rotary Drum Filter...
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There has already been a lot of conversation about the RDF so I will not go into much detail about it but I will simply say it is self cleaning mechanical filter that will remove particles of 40 microns and larger from the water column. The dirty water enter into a 40 micron SS mesh drum where all of the solids are filtered from the water. As the micro-screen gets clogged with waste it gets more difficult for the clean water to pass through the screen which raises the water level inside the drum. This water level is monitored by proximity switches so that once the level gets to a certain height it triggers the filter to clean itself and remove all of the trapped waste from the filter. In the rare occasion that the filter doesn't require cleaning within 1 hr of operation the filter automatically cycles so waste is never left inside the drum for longer than 1 hour. This greatly reduces the amount of dissolved organic carbons (DOCs) that are released into the water which is always a good thing. The mechanically clean water then travel from the RDF into the biological filter.
Recirculating Biological Filter...
Water enters the biological filter through the three 4" inlets (Letter A). The water mixes with the water at the top of the filter and begins to travel down through the static submerged Cermedia filtration media (Letter B). The Cermedia is a man made ceramic block that has thousands of interconnected pores through the media. These pores allows for the water to easily travel through the media utilizing the massive amount of surface area contained inside each block of Cermedia. The surface area of the Cermedia is colonized by nitrifying bacteria biologically filters the water so that it is safe to send back to the pond. After the water travels through the Cermedia it returns back to the pond through the filter outlets (Letter C). Some of the water that has passed through the Cermedia bed is transported back to the top of the bio-filter through the center airlift riser tube (Letter D). This allows for maximum exposure to the nitrifying bacteria to make sure the water is as clean as possible before going back to the pond. The airlift riser tube is just a 4" pipe with an air stone dropped into it to create the water movement. This airlift doesn't have to be very efficient because it is not lifting the water but merely transporting it from the bottom to the top of the filter.
As mentioned in the video the airlift riser tube can also be retro-fitted with a UV clarifier to kill the algae spores that might be in the water. I will get into more detail about this later in this thread.
I am sure you have many questions about this system so please ask away!
Thanks for making the video!
I am interested in the airlift part.
You have four 3" airlift riser tubes with a submergence depth of 44" using a Hakko 100L linear air pump which supplies approximately 20 - 23 lpm to each airlift tube.
My question is do you think I can duplicate the flow in one 3" airlift riser tube with a submergence depth of 44" using a Hakko HK-25L linear air pump?
The Hakko HK-100 Linear air pump:
The Hakko HK-25L Linear air pump:
The graphs shows water depth in feet. 44 inches is about 3.67 feet.
Super freaking cool!
This is my opinion. It is worth exactly what you paid for it.
Just saw this post.Very impressive!
I dont understand this things:
The air pump, in this case a Hakko 100L, compresses air and pumps it into the injection manifold at the bottom of the airlift (Letter B). The injection manifold distributes the bubbles inside the contact chamber of the airlift (Letter C)
What is an injection manifold , how it operates?
There is no need for an additional fines filter. The sieve filters down to 40 microns all the time but as the screen clogs the openings reduce and smaller particles are trapped. Here is a good representation of this...
This is what the water looked like after I poured in all the Cermedia (I did not waste the dust off before adding)
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The dust particles were smaller than 40 microns and were dissolved into the water forming a white cloudy water solution. I could see this cloudy water coming through the RDF so i knew the particles were too small. However as the drum screen got clogged the cloudy particles would get stuck on the smaller openings and in about three hours the water was nice and clear again!
This is what the water looked like
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