water manifold!?

OK- step by step instructions don't apply, as design is determined by application.

-Create a main manifold out of 1/2" poly hose. If you are running open 1/4" feeder hoses, or unregulated (basket) drip stakes, it is desirable to create a circuit ( say you've got 16 pots in a 4 pot by 4 pot square and you want to run open tube- it makes sense to make a square manifold, which will keep your feed pressure more regular) If you're using regulated emitters, it doesn't make any differance- You can just use a straight hose and plug the end that's not attached to the pump. Of course, you can also use elbows and tees as the spirit moves you.

- Punch 1/4" barbed connectors thru the 1/2" tube wherever you want to put in a feeder line. Do they have to be regular? Depends... Should I use tees? Maybe- they change flow in an unpressurized sys a lot, less @ +pressure, you might like the changes or not...Depends...

-Insert button drippers at the end of feed line if you're using button drippers, or not if you're not. Place emitters ( an open tube is also an emitter, by default- just a really coarse one) where you want them.

-Attach pump output to manifold, intake to res ( or drop it in if submersible), power pump, fix whatever needs fixing.

Anyway- If you're not using a regulated emitter, you want your 1/4" feeder tubes to be about the same length, so you have about the same flow rate to each pot. (Essentially, the 1/4" feed tube acts as the regulator, as it presents the most resistance to flow thru the system- ya know how you get better pressure thru a short garden hose than a long one. ) Differing lengths of 1/2" don't present the same issues, as they present less resistance to flow.

With an open-ended system, it is possible to get good balance just by bringing up the pressure, regardless of varying drag to each hose end- but you won't get balance that way until your capacity to build pressure within the system exceeds the capacity of the system to discharge pressure- with many open-ended 1/4" hoses, this is a whole load of water moving, much more than I can imagine you want.

Regulated emitters are much easier to, well, regulate. Button emitters work really well to give you the same flow from each emitter across the system- I highly rec them, unless you are using some a lot of organics, as they tend to clog the very fine apetures of the buton emitters.

Take a look at Dripworks Drip Irrigation Design Overview and look through their design tools and faqs- they're geared toward differant applications than I imagine you're thinking, but the design principles are the same.

Hope this helps.