Well I did some calculations to figure out how many holes of what size I would need to have to equate to the same flow rate. So what I did was steal someone else's equation!

Anyways I calculated the area of my outlet tube. So you would find the diameter of the pipe that the water is coming out of. Which mine was 1/2". Then I plugged that into my equation: 3.14 x 0.5^2 now since that is the DIAMETER of the hose you would divide your answer by 4. I got about 0.1935 when all was said and done. Then I did the same but Instead of the hose diameter I used the diameter of the drill bit. I did three different drill bits, 1/16", 3/32", and 1/8". Once you get your decimal number you take your hose area and divide it by the drill bit area to get the number of holes you'll need. This is what I got for the number of holes for each drill bit.

1/16" - 64 holes

3/32" - 28 holes

1/8" - 16 holes

I decided that I was going to go with 28 holes with a 3/32" drill bit. So I figured it would be about 1 hole per inch. So I went ahead and made my marks. Then I drew a straight line so that my Holes wouldn't be all willy nilly. Now when I did this I realized that I would only have 24 holes, but that would be alright because I didn't factor in the thickness of the wall of the pipe. So what I did was drill an extra 4 1/16" holes that were above the other holes to help with surface movement.

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Then I went ahead and drilled them.

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Here you can see one of the little holes.

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So this is what one side looks like. I then went ahead and did the other side. Now since I had let all the PVC glue dry over night once I was done I decided to test it and see how it worked with the garden hose. It worked excellent! So then I did a once over and sprayed off any residue left my chemicals and went to install it! It was a tight squeeze because of the rim of the tank but I got it to fit. The hose fitting was also too big but I got the hose to fit over it with a little muscle. I fired up my filter again and below are the results.

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My fish already seem waaay happy now that the air stone is gone. I think before they were scared of it because they would just stay to one side of the tank but right now they all are over on the other side exploring. Im really happy with it so far and a nice feature is that I can have one side of the spray bar pointed towards the surface and the other down towards the bottom.

So let me know what your guys think!! I do still plan on making an intake as well but I need to buy some more parts and do some more research. I think I'm going to try a few different combinations of intake pipes and see what I like best. BUT Stay tuned for even more!

goldfinger said:

I can't remember if head pressure is greater than aperture pressure, but I know pressure increased as small aperture goes?

Try it and see mate depends length of the pipe and if you have differing head pump presure aswell?

Well I used all the same size holes except for the 4 smaller ones and from what I can tell all the holes produce about the same amount of pressure. If not its really not noticeable I don't see the need to make them different sizes