SO I WAS THINKING OF RAISING MY TURNOVER RATE IN MY TANK AND WANTED TO KNOW THE BEST WAY TO MATCH SYSTEMS. I HAVE A CHEAP OVERFLOW BOX GOING RIGHT NOW WITH ONLY 500 RETURN. ABOUT 6' OF HEADLOSS TO ACTUALLY ONLY GIVE ME AROUND 250? THIS IS FOR MY 150G FLOWER SO I DONT NEED A LOT BUT WOULD LIKE TO GET MORE THAN A MEASLY 2-3 HUNDRED!! IF I AM CORRECT, IT SEEMS AS IF I NEED TO GET A BOX AND MATCH THE PUMP TO IT INCLUDING HEAD LOSS. MY SYSTEM DOES NOT HAVE A BALL VALVE TO RESTRICT IF THE PUMP IS NOT RIGHT. SO IF A MODEL 15 PUMP PUMPS 1500GPH AND SAY 1100GPH AT 6', WOULD I NEED A BOX WITH AN 1100GPH RATE?