It is very easy to calculate how much water will backsiphon in a power outage. L x H x W /231. Take the length and width of your display and the depth of submersion (H) of the Loc Line and play with different Loc Line placements until you are comfortable. For what its worth, my 100G reef is 13 years old with a 30G sump and I use submerged Loc Line returns and I have never once come anywhere close to a flood when the power goes off.
My Loc Lines are 3/4" below the surface, the tank is 60" long and 18" wide. 0.75x60x18/231= 3.5 gallons maximum that can possible backflow to the sump before the Loc Line is exposed to atmosphere and the siphon breaks. we all know water cannot jump uphill so once the Loc Line end is exposed the flow quits. No cleaning, no drilled holes and noise, no headloss through a check valve and no false sense of security, it works every time and will not fail. The best form of backflow prevention known to man, an air gap.
My sump is 30G and normally runs with say 18-20 gallons in it so plenty of freeboard or spare room to hold 3.5 gallons or even if the Loc Lines were lowered to say 1.5" 7 gallons of water. Never lost a nights sleep worrying if a check valve is going to hold or if a drilled hole is going to get plugged with algae. You could clean a check valve right now and in the next 10 minutes the power goes off or you shut it off and a chunk of food, piece of algae, small snail or whatever can lodge between the seat and flapper and render it useless. It does not have to be a catastrophic failure, even a trickle will flood in time and its usually in the middle of the night or when you are not home this happens.
False sense of security and waste of hard earned money.
My Loc Lines are 3/4" below the surface, the tank is 60" long and 18" wide. 0.75x60x18/231= 3.5 gallons maximum that can possible backflow to the sump before the Loc Line is exposed to atmosphere and the siphon breaks. we all know water cannot jump uphill so once the Loc Line end is exposed the flow quits. No cleaning, no drilled holes and noise, no headloss through a check valve and no false sense of security, it works every time and will not fail. The best form of backflow prevention known to man, an air gap.
My sump is 30G and normally runs with say 18-20 gallons in it so plenty of freeboard or spare room to hold 3.5 gallons or even if the Loc Lines were lowered to say 1.5" 7 gallons of water. Never lost a nights sleep worrying if a check valve is going to hold or if a drilled hole is going to get plugged with algae. You could clean a check valve right now and in the next 10 minutes the power goes off or you shut it off and a chunk of food, piece of algae, small snail or whatever can lodge between the seat and flapper and render it useless. It does not have to be a catastrophic failure, even a trickle will flood in time and its usually in the middle of the night or when you are not home this happens.
False sense of security and waste of hard earned money.
