newb tank question

I recently put together my first sw tank, have a few circulation questions. I want to keep sps corals. I have a 14 gallon biocube with a DIY overflow, a 5.5 gallon sump. My problem is, to have everything running smoothly I have the return pump cut back and im getting about 60 gallons per hour coming from the overflow, I know not a high number, I have a circulation pump rated at 240 gph in the DT. Can I add this up to be 300 gallons per hour, or is that not correct, and I would have to go by the 60 gph number? from what I have read that isnt enough for sps, or other life for that matter.

 

Yes, you do count the return towards your flow. So 300 GPH in that tank is probably 30X turnover (assuming the actual volume in the tank is around 10 gallons). For SPS, you want to be in the 500-100X range. So adding another 300 or so should get you to where you want to be.