quick thoughts on skimmer design

[Phishy]

I got a guy who can get me clear pvc, probably free in any size and length I need, but he needs my specs, I will offer to make him one also, if he wants. He tried to make one once he told me with a airstone design and wasn't happy with it.

I am going to mod this design, http://w3page.com/fishline/gif/ventskim.gif

The one i drew up on paint is too large to upload, so bear with me.

The venturi will be replaced by a beckett (I will build a housing with a needle valve), and I will maintain the 1" tubing with the beckett into the skimmer. It will stop about 1.5 inches from the bottom.
housing design: http://ozreef.org/diy_plans/protein_...r_housing.html

The tube in the skimmer will be 2.5-3in in diameter and be at least 8in long and be about 3 inches from the top of the main cylinder.

The main tube will be 6in diameter, possibly 8in. The cup will be 6/8in and the tube comng up from the cup will be the 2.5-3in tubing.

For the outlet, I was debating 1in vs 2in with a gatevalve on it, I am leaning 2in, incase I need to open up the flow more. And I wasn't going to have the elbow on the output, just straight out from the bottom (it will be insump)

All the beckett designs I have seen have the beckett pointing down, is this necessary? If it is I would have the beckett going in at the top and the elbow going into the beckett.

Thoughts on length, spacing and diameters woudl be greatly appreciated.

[Phishy]

The articles I read recommended the 1in intake and also stated that the air bubbles become fully saturated at 13cm(8in) hence those dimensions I mentioned.

[Shaqinwi 65]

I am about to embark on a DIY skimmer journey also, although I'll be paying for my PVC .

Can I ask why you decided on a venturi vs. needle wheel skimmer. I was thinking going NW because they appear to be more efficient. Could be wrong though, all the differing opinions will make your head spin.

[Phishy]

I am actually doing a beckett which should give better production then the venturi, I am not sure how to go about making a nw.

After reading the Chris Paris article I decided the beckett was the best bet, and will process the most water efficiently, that is just my opinion on it.