Hi,
you can have access to another article with several pictures showing the filtration system of Fruto's pond, fully air driven.
I'm very sorry it is available only in spanish, but hopefully you will find that just the system sketch and the pictures are worthwhile to see.
Basically he's got 4 airlifts pumping water from the pond into de filter: 2 of them are 110 mm diameter pipe, placed at the two B.D. pipe intakes. The other two are placed at the two Skimmer intakes. Remember, no airstones in the airlifts.
The water goes to a mechanical stage with static K1, there is an interesting automatic system for cleaning and rising. Then to a second biological stage. Then to the pond. Maximum difference of water head is just around 1.5 cm
This is the link to the article:
http
://www.elkoi.es/index.php?option=com_co ... &Itemid=47" onclick="window.open(this.href);return false;
You can also have a look at a couple of videos. In the next clip you can watch the filter doing his job, except that there was not chaotic movement going on in the biological filter stage at that precise moment.
Two airlift (110 mm pipe) pump the pond water through the two bottom drain pipes into a filter chamber. Remember there are other two airlifts, not seen in this clip.
Several big slipping gates allow the water entering the second mechanical stage through 110 mm holes, this stage is almost full of static K1. Notice a sort of blue float supporting a device. It is an automatic system. When the K1 is dirty it is more buoyant and rises. The device switches a double circuit, stopping the main air pump used for the airlifts and starting a second air pump used for cleaning the static K1, but you can see this in a secong clip.
The water exit the mechanical stage through 4 slipping gates. You will notice that these gates will shut as soon as the water flow is stopped, this is very convenient for automatic cleaning of static K1
This is the link to the clip
http
://www.youtube.com/watch?v=_JmpazQMEsk& ... annel_page" onclick="window.open(this.href);return false;
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In a second clip you will see what happens after cleaning the static K1 and draining the dirt. The secondary air pump used to clean the static K1 automatically stops, and the main air pump start again blowing air to the 110 mm airlifts (you will see just two, but there are other two attached to a couple of skimmer intakes). More pond Water is pumped by the airlifts through the two bottom drain pipes into the filter. Notice at the rear part of the filter that the slipping gates are partially open alowing the water outflow passing through
http
://www.youtube.com/watch?v=6jjFe-wB7x4&feature=channel" onclick="window.open(this.href);return false;
Hope this might be of some help.
Diego