help with water pumps

[kwirky]

how large is your tank? that'll contribute to the head pressure. 50 gallons of water trying to force it's way against your pump can be almost 3' of head alone.

if you already bought it, do an experiment. go to the bathroom, hook a hose to the pump, and raise a 5 gallon bucket up the same height as your tank. then time how long it takes to fill the bucket. that's your water flow at the head pressure WITHOUT your tank's water forcing down on the pump. it'll give you a rough estimate if your pump's strong enough to at least get the water to the bottom of the tank at the flow you want.

oh, and if you have a gravity fed overflow at 3/4", then reduced to 1/2", i'd be careful. that can only handle a flow of about 90 gph, since it's gravity fed. and each 90 degree elbow will reduce that flow by 25%

how big IS your tank? is it a nano?

[mark]

Max head is where the pumps rolls off to zero output.

Depends on pump curve, how return is routed but guessing your bulkhead/hose could handle your pump volume from that head. Seems common advice to restrict pump output with a value, to prevent overflows maxing out and tank overflowing.

Often numbers like 3/4" bulkheads rated 300gpm, 1" - 600gph. Could check those numbers against how overflow or tanks manufacturers rate volume.

[JOSH]

its a for a ten gallon nano, im expecting to lose some of the GPH rating but i should see a fair increase in flow compared to the 250gph canister im using right now i would imagine