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Very soon Bradreef, very soon. Hahhahahahhahaha Just have to finish my boards and hopefully I'll get the chance to play with one of these guys.

Peace,
John
 
According to Escobal in Aquatic Systems Engineering: Devices and How They Function, the upper limit of air injected into a skimmer is 13% of the water volume inside the skimmer. More than that and the additional air causes the micro bubbles in the skimmer chamber to burst and form larger, less efficient bubbles.

The hard part of this from a practical standpoint is figuring out just how to determine when you have the air/water ratio correct. I think the best way to do it is to shut off your air pump and mark where the water level is, and then dial in enough air so the water line raises to a level 13% higher than before (multiply the water level by 1.13 to find the level with air). If you have a square mixing base at the bottom of your skimmer, you could dial a little bit more to make up for the extra volume in the base.

I have a feeling that a lot of you will end up using much less air than you were before, but this is where the skimmer should be running at maximum efficiency. You may have trouble getting the foam up and out of the neck on taller skimmers. In this case, either increase the water level in the skimmer or cut down the riser tube until you get the dryness of foam you're looking for.

Mike
 
I have his book, the 13% is a theoretical and is framed by "About" not the upper limit. But I do agree it is something in that approximate zone. If you look at the calculations behind it, it figures on a solid bubble/water mix, when in most thier is a good section of the skimmer tube that is not saturated. I would say the number should be closer to 20% maybe a tad more.
As have said start low and work your way up with the air looking for the sweet spot for bubble size and production. On the length of the neck, on the first skimmer I did the foam climbed up 5 feet in a 8 inch tube (not to much problem thier) on the second model I wanted to have a larger mixing chamber, now the foam rises up 2 feet in the neck.

Redeye, I poked a tiny hole in the line just prior to the valve and then turned the pump down. Shoot me a pm with your phone number and we caan talk if you wish


MIke
 
Mojo, what did you turn down? When poking a hole in the air line did you put in a valve?

I just can't get over how much cooler my tank runs now. Thats almost as exciting as the flexiblity and effectivness of the air stone skimmer.
 
hey Mojo,

I just found out from Eco Systems I need bigger stones to match my skimmer/air pump (or bleed more air off) which I have ordered. I think I may have ripped the diaphram trying to push more air then my current stones could handle? Now my air flow meters aren't reading as high and my bubbles in my skimmer look bigger. My 4 - 6" stones will be here soon but my replacement diaphram is 8 weeks out. I haven't tore apart the air pump yet to confirm a hole in the diaphram.

I state all this because I thought you have replaced a diaphram? What did you notice in your skimmer when it tore?

This confirms for me that Air Drivin skimmer are not about how much air you can run but to match the air to your skimmer. We have entered a new area.
 
Update,

Hello shaving cream.

I took out my internal mixing chamber to open up more room around the air stones, installed 4 - 6" fine pore air stones, ran each stone a 3/8" line, turned each stone with point facing down (45' angle), and changed out my feed pump to a 600 gph Eheim. WOW. :eek:

I can't believe the difference. :D After talking with Mojo and Aquatic Ecosystems I figured out some mistakes with my original conversion. These air pumps need to breath and with air stones putting out this much air (running 95 scfh through skimmer and still bleeding off some air) they make smaller bubbles when they are not working hard. At first I was going high psi in a small mixing chamber, maxing each stone air capiblities, and my bubble size was starting to increase. Now with each stone not running to its max, more room around them, and orientating them correctly, the difference is big.

Well worth the extra work.
 
Now, that looks frothy! :) Makes me wish I had bought the larger stones now, but I'll just bleed off more air to make the 3" stones work better. Thanks for the update Redeye, I think as we learn more about the working parameters of the stones and air pumps that drive them, the performance will get better and better!

Peace,
John
 
redeye,

How'd you point the stones down at 45 degree angles. From the pics it looks like they are just pointing straight out from the bulkheads?

Peace,
John
 
John have the points of the stone point to the bottom of the skimmer, so the flat part of the stone snt pointing to the bottom.


Looking good redeye, Got Foam


MIke
 
Yep,

Sorry for the bad explanation. The stones themselves are flat and screwed into the bulkhead till they the square edge is 45' to horizontal. Works great.

I really think the bigger stones and tubing made a very significant difference.
 
recommendation for a pump and 1 or 2 stones for a ER 6-2+ knock off. say i wanted to make it like yours??

Lunchbucket
 
That is something I'd be interested in knowing as well...but would the reaction chamber be tall enough to see any worthwhile gains?

Nick
 
nevermind....duh, NeedleWheel.....
I dont have to be smart, my fiance says I'm cute.

Nick
 
I am with ya on those idea's luchbucket. Maybe starting with a smaller needlewheel pump to slow the flow and increase the contact time for the bubbles if you add stones.
 
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