Carboy pump cleaning station question

Building a pump-in-a-bucket cleaning station for carboys, to use with Cleaners and sanitizers. I'm wondering what diameter people are using for the pipe into the carboy to allow enough exit flow?

I bought http://www.harborfreight.com/620-gph-submersible-fountain-pump-68393.html

I'm wondering what people are using to get the job done. 1/2" (I found some 1/2" CPVC with a thinner wall, not sure what schedule it is) or do I need to find thinner?

Also wondering what people are using to avoid excessive foaming while running.

I use a 1/2" rigid copper pipe, actually 9/16" diameter hooked up to a 1/3rd HP sump pump. It has enough water flow and pressure to lift a 6 gal. Better Bottle off the pipe if I don't hold it down. The Oxiclean drains out at first, but when the foam builds up it quits draining. I have never had it not become clean by that time so I don't worry about it.

It also cleans corny kegs before the foam starts to overflow.