Pond Boss Forums INTRO Questions & Observations What pier diameter for dock

As for size, I haven't got a clue. But, for reinforcement, use rebar. See if you can find someone to make a couple of circles of #3 or #4 rebar (I'd space them 2' to 2 1/2' apart vertically) and tie in #4's or #5's insice of the circles.

Since concrete is porous, I'd look into getting the rebar epoxy coated to protect against them rusting and breaking apart the concrete.

You got a vibrator to make sure that there aren't any voids in the concrete once it's poured into the tubes? How were you planning on attaching the actual pier to the concrete tubes?