Since no one has chimed in, I'll give this a go but take the information with a bit of salt.
IndyAquaponics wrote:
Do i want a pump with adjustable flow or is it better to just put a ball valve inline back to my FT?
Either would work, most probably just use the ball valve and a regular pump. I've used the Laguna Max-Flo pumps this way for years and they are holding up well. I think it's more important to get one that has the ability to handle solids.
IndyAquaponics wrote:
When sizing your pump do you plan for total system volume cycled once per hour for flood and drain system?
We usually suggest turning over the fish tank volume once per hour, not the total system volume. It's good to buy a pump that has extra capacity for aeration and if you are planning on expanding your system later. You also need to look at the flow rate for different head heights. Most pumps have a chart for this (head height is measured from the top of the water the pump is in to the highest point it pumps to). Are you going to be doing continuous flow, flood and drain with siphons or timed flood and drain? It makes a difference in the pump sizing because the pump has to pump the volume of the fish tank in however long it's on.
IndyAquaponics wrote:
Most pumps come with 1/2" outlets, does that mean just run 1/2" return line or is it better to expand that to something larger?
This depends a bit on distance, number of elbows and other things. A lot of people will actually upsize the outlet pipe from the pump to reduce friction losses. As far as the return pipe, it's better to go larger - if you do a google search for gravity flow pvc pipe size you'll find some charts and info on vertical and horizontal flow rates.
Backyard Aquaponics
