Plumbing my nano reef tank


Reefing newb
So, I want to set up a 20gal sump directly beneath my display tank. I have 2 small pumps 300gph one for the display tank to drain into the sump and one to return the water back to the display. Currently all filtration devices are attached to the display tank and 6 have had some awful battles with algae. I have read several posts before posting my own, thecquestion is are myv2 pumps sufficient, do I usec1" PVC for the drain line and return line?