what size do i use for in/out of pump

[DrDave88]

I know this is a common question, but i would like to know why-

hypathetically - say i have a 3/4 in and out of my pump, and i am pushing the water from under my tank up to above the tank. What dimension pvc would i use? Figure it is a 75 gallon RR with two overflows. would i use 1" from each overflow into my sump, and then 1" back to my tank from the pump? i ust don't understand the rule of thumb on in/out sizes of piping...

dr

 

[danmhippo]

It has been a while since I do the plumbing, but I believe the line returning to the main tank should be equal or smaller then the one's going to the sump. The reason behind is that if your return line to the main tank is much larger then the overflow to the sump, you may have problem with maintank draining and the main tank overflows.

We usually don't worry about the overflow pipe being too large as whatever the volume of water pumped up from the sump to the main tank will always be the same volume going back down.

 

[DrDave88]

so is it correct to assume that i can put whatever size pipes from the tank, assuming that i have valves to fine tune the flow, into the sump, and then have a pipe matching the outflow size of the pump for the return line?
ex. 3/4" out flow assumes a 3/4" pipe leading to the top of the tank from the pump? I have seen that some people have been uping the size by a quarter inch from the size of the outflow to the pump to the top of the tank. is this safe? if correct, i think i have my plans already done!

i jsut saw a 110 tank, decent lights, sump, and stand for three hundred. i am so stoked!

thanks for the beginner help
-dr

 

[SPC]

Posted by Dr Dave:

so is it correct to assume that i can put whatever size pipes from the tank, assuming that i have valves to fine tune the flow, into the sump, and then have a pipe matching the outflow size of the pump for the return line?

- I would reccommend that you oversize the pipe to your sump. This pipe size cannot be to large and the bigger the better in case of accidents such as snails or other objects being washed into it. The valves are not necessary on this line but one should be placed on the line leaving the pump.

I have seen that some people have been uping the size by a quarter inch from the size of the outflow to the pump to the top of the tank. is this safe? if correct, i think i have my plans already done!

-It is not necessary but is ok. The larger the pipe the less friction which means less head loss.
Steve

 

[dizzy]

so is it correct to assume that i can put whatever size pipes from the tank, assuming that i have valves to fine tune the flow, into the sump, and then have a pipe matching the outflow size of the pump for the return line?

I agree with Steve about the size of the drain lines being as large as possible. Besides the clogging issue they can be very noisy if undersized.
Reducing flow to reduce noise is a poor trade off. Use sweep bends in the return line instead of sharp 90 degree bends if possible to reduce head loss.

PS Steve made the good point about putting the valve in the return line. Never starve a pump for water or it may overheat. People who don't clean out pond filters replace a lot of pumps.

I can't type or spell.

 

[aquarist=broke]

How many gallons per hour will a 1" overflow blukhead drain?

Does anybody know or test that?....

 

[dizzy]

Depends on how low it is placed in the tank. If it were in the bottom of the back wall it could drain a lot. The question is how high will the tank fill before the water is drained off.