More fun with plumbing...

I am building a closed loop system powered by a Velocity T-3 (800 gph) using
http://www.sparklingfloorservice.com/tank/closedloop.html as a rough
pattern.

The SCWD instructions mention pre-filtering the intake to prevent debris
entering yet I notice that most folks just run a regular piece of filter
intake or drill PVC as illustrated.
Using a 24 inch (capped on the bottom) section of flex PVC as my intake I
have drilled over 100 holes each an eighth of an inch in diameter.
Will this suffice? Both as providing enough flow for the above mentioned
pump *and* limiting debris infiltration? Do I need a "sock" of some sort
(sponge/or manufactured pre-filter material) over top this?

Also- the little metal hose clamps (worm clamps?)- may they be exposed to
saltwater? Not directly *in* the water, but say running right along the rim?
If this is not advisable are their plastic clamps available that I have not
yet found?

Thanks once again for the help- I'm getting there...

-- 
Toni
http://www.cearbhaill.com/aquarium.htm