Recommended diameter of water pipes ?

[Bob Vento]

Which is the most commonly uses diameter for the PVC pipe, joints and valves being used in Aquaponic gardening today?

I have a bunch of 1/2" stuff, but I think that would be too small of a diameter for my system. I looked for some discussion here and did not see any right off.

[TCLynx]

Yes if your heights of things allow, the sump tank can be above ground.  However, if your grow beds are sitting on the ground, you would need a slope to allow them to drain into a sump tank that is not buried.  And shallow sump tanks actually need to be bigger than one might expect in order to have enough volume to keep the pump from sucking air because remember that most pumps need several inches of water in the tank in order to keep them from sucking air.

(warning following paragraph is more an advanced concept for sprawling systems that keep growing and changing.)

Anyway, I do some systems where the pump is in the troughs under my towers.  One just needs to be careful to keep an eye on level fluctuations the shallower the sump is and when connecting tanks together to act as a single larger sump, the size of the plumbing connection and height of it can become critical, I've spent hours watching a new change I've made and hoping I wouldn't have to dig up and re-do a plumbing modification because I didn't over do the plumbing size.

[matthew ferrell]

Agreed- You will most likely need a larger foot print sump due to the height limitation.