Ok I have a 45 gallon folr system and was just running fluval 404. Decided to go to sump made one out of 20 gallong long. Using the rio 2500 return pump and corallife 125 skimmer. My question is since the tank is already full and cannot drill. I am using my fluval 404 with the cannister empty as means to pull the water from the tank to the sump. Is this an ok design, should I anticipate any problems? I've heard horror stories about siphon overflows. I did a power off test and no spillage.