in-line pumps vs submersable

[whiskeyinajar]

wich is better and what is a good gph for a 4ft tall bong cooler. I'm thinking 300 will do.

[Rob Cork]

Obviously a submersible pump will require a reservior, but I guess you could incorporate that into a bong setup. The main disadvantage of submersible pumps as I'm aware is that the heat from the motor goes into the water, as the whole pump is immersed. 300gph ought to be ok, but what you really want to look at is the max. head height (or whatever they call it) - the specs for a pump should include a maximum height to which it will pump water.

[cjtune]

I have a 24W 400gph submersible pump. Since all electrical motors are quite efficient, you probably won't need to bother about the extra 2 or 3W of waste heat form the pump (compared to a frickin' 80W Tbird). Generally, most submersible pumps (or powerheads, as the aquarium fellas call them) are designed to deliver high pressure (head), and will provide head in proportion to the flow rate. My uncle, who's a aquariums hobbyist, told me that submersible pumps tend to be more reliable than inline pumps -he's had two inline pumps fail on him but no submersible ones. Probably due to the fact that the water provides better cooling than air (for the pump) as well as a continuous source of lubrication.

[Richard]

This correlates with my experience.

I too prefer submersibles.

cjtune (Jul 02, 2001 06:54 a.m.):
I have a 24W 400gph submersible pump. Since all electrical motors are quite efficient, you probably won't need to bother about the extra 2 or 3W of waste heat form the pump (compared to a frickin' 80W Tbird). Generally, most submersible pumps (or powerheads, as the aquarium fellas call them) are designed to deliver high pressure (head), and will provide head in proportion to the flow rate. My uncle, who's a aquariums hobbyist, told me that submersible pumps tend to be more reliable than inline pumps -he's had two inline pumps fail on him but no submersible ones. Probably due to the fact that the water provides better cooling than air (for the pump) as well as a continuous source of lubrication.