informative thread on overflow pipes

[BR549]

www.sal****erfish.com , message boards, equipment & diy, return pipe size



Fender posted:

For future referenc:

PIPE SIZE
MAX. FLOW GPM (Gallons Per Minute)
MAX. FLOW GPH (Gallons Per Hour)

1/2 "
3.5
210

3/4"
6
360

1
10
600

1 ¼"
20
1,200

1 ½"
30
1,800

2"
60
3,600

2 ½"
100
6,000

3"
175
10,500

[Timothy Tom]

Where did these numbers come from? Does it also depend on the
pressure head (i.e. the distance from the drain hole to where it is
flowing, that is directly related to the flow? I have an ampmaster
3000 which according to its flow chart should be pumping approximately
3000 gallons an hour with an upward 4 ft. pressure head. I only have
a 1" drain pipe, and if your numbers are correct, I should have 2400
gallons an hour of my aquarium water overflowing the tank. Granted
pumps may never be as efficient as advertised, but I doubt I am only
getting 20% efficiency, since I am using all the recommended diameter
outflow plumbing.

[BR549]

Fender on sal****erfish.com posted them, I know the 1" flow is a little over
rated, my Little Giant 4mdqx-sc (1200 gal per hr @4 ft head), swamped my 2
overflow pipes, which are 1" thin wall pvc, I had to add an overflow box,
diverted water to my 50 gal refuge and my protein skimmer, the girl at the
picnic says, "bigger is better", it is hard to redo it after it is done, for
upgrades...etc. use as a guideline not the Bible.

I am setting up a 250 gal 15" tall hex, and I am going to use 2 Little Giant
4mdqx-sc pumps with 2 2" thin wall overflow pipes.

br549


"Timothy Tom" > wrote in message
m...
> Where did these numbers come from? Does it also depend on the
> pressure head (i.e. the distance from the drain hole to where it is
> flowing, that is directly related to the flow? I have an ampmaster
> 3000 which according to its flow chart should be pumping approximately
> 3000 gallons an hour with an upward 4 ft. pressure head. I only have
> a 1" drain pipe, and if your numbers are correct, I should have 2400
> gallons an hour of my aquarium water overflowing the tank. Granted
> pumps may never be as efficient as advertised, but I doubt I am only
> getting 20% efficiency, since I am using all the recommended diameter
> outflow plumbing.
>