return intake dia

[kzickovich]

I just got done running all my plumbing up to my fish tank from the basement where I set-up a sump and refugium. I plumbed everything 1.5 dia what size dia should go into the tank? My tank isn't drilled so I'm going to have to come over the top. I'm just not sure if I want to reduce it down to 1 or even 3/4 inch. The reduced line will only be about 5 feet.

[jdieck]

Depends on the amount of flow (size and capacity of the pump) In general is easier to handle outlets to the tank of smaller than 11/2" dia so it is usual to split the 11/2" to at least two small diameter outlets whose combined sectional area aproximates the sectional area of the 11/2" pipe.
As the sectional area of a 11/2" pipe is 1.77 sq inches and the sectional area of a 3/4" is 0.44 sq inches I would use four 3/4 outlets for a total of 1.76 or two to three 1" outlets whose sectional area is 0.79 sq inch each. for a total of 1.58 sq inches.

In my 225 I have 11/2" inch return that reduces to 1" right above the tank and to three 3/4" right after.
Under the canopy I have two branches and the return flow switches from one branch to the other every 20 minutes.

Here is a pic with the canopy removed.

[kzickovich]

I have the outlet from the pump T off in the basement and coming up with two 1 1/2 pipes so would that be T off of each for a total of four 3/4 inlets

[jdieck]

Originally posted by kzickovich
I have the outlet from the pump T off in the basement and coming up with two 1 1/2 pipes so would that be T off of each for a total of four 3/4 inlets

What pump are you using? Seems that two 11/2" lines will have very small friction head loss and the water velocity trough the pipes can be very small. You can increase water velocity to have more random and turbulent flow in the tank by reducing the diameter at the tank point depending the total flow expected at the tank (Pump flow at the given head from the basement to the tank) two 3/4" for each 11/2" lines is more likely enough although some velocity increase is expected.

[kzickovich]

I have a reeflo barracuda 4680 GPH the overall run is about 12 feet most vert. the t is at the very end may be two feet then five feet up

[jdieck]

That will give you about 2300 to 2500 gph. Assuming your overflow can take that volume you may want to add a couple more 3/4" outlets.

[kzickovich]

thanks for your help that is about what I was thinking I have a valve on both 1 1/2 pipes to slow flow if needed

[jdieck]

Good. Just keep in mind that slowing the flow too much may cause more heat transfer to the water but there is really no way to find out until the installation is finished.