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jda
01/24/2007, 01:32 PM
This is all probably posted in a marathon post somewhere, but here is what I found.

I modded a sedra 5000 and a sedra 9000 pump. I did everything just like everybody else. I borrowed a meter and I was pulling about 28-30 units (forgot what they were).

After the mod, I was also pulling in too much water and the skimmer chambers were too turbulent. I put a T on each pump and this helped a LOT.

Then, I got to thinking. I need to figure out how to get more air and less water. At the suggestion of another local, I took some putty and made the intake around the venturi a lot smaller. The increase in velocity in the neck really pulled a heck of a lot more air. I also decreased the turbulence in the chamber - which was good. Unfortunately, I don't have the meter anymore so I cannot measure. At one point, I increased the veloicty so much that you could cavitate the pump with all of the air. Luckily, I got the putty out and redid the job.

Next is to figure out how to increase the air by veolicy in a better manner than putty in the venturi neck.

RandyStacyE
01/24/2007, 03:20 PM
What mesh did you use and how many layers did you use?

After doing the 'mesh mod' how long did you wait before making your final conclusions?

I only ask these questions because when I did the mesh mod I used the PF4 mesh – 3 layers.

Immediately after the modification ... the results are NOT impressive at all. I had increased turbulence, bigger bubbles and less bubbles than before. You MUST give it time to 'break in'. In many (if not most cases) this takes overnight. The changes are remarkable, but you must give it time and be patient.

You shouldn’t plug it in, say "this sucks" and begin making other alterations. The transformation will happen on its own.

Typically the mesh mod enables the pump to draw much more air and the mesh wheel itself deals with the air (chews up the air) much more effectively than a needle wheel.

jda
01/24/2007, 03:25 PM
I used 3 layers of the PF4. I had to trim most/some of the 3rd layer off to make it fit, but there is some of the 3rd layer on there.

It had been running for a few weeks before I did anything.

The mod draws more air through the same intake because it moves more water. I was trying how to figure out how to get even more air. Velocity is the key. Chopping the air smaller is another key.