help: filter flow, step up step down valving...

[mellowvision]

I just got an 80 gph mini canister filter for my 15 gallon, which I am building into a paludarium. It uses 3/8" ID tubing for the intkake and return.

today at lowes I found a nice ball valve that is 1" ID along with a 1" OD to 3/8" OD (1/4" ID) step down barb with threads on one end. these parts, for 8 bucks or whatever, will allow me to disconnect the filter without removing the intake/return pipes from the tank, which is desireable since I'd like to hide them. I am worried about stepping down to 1/4" ID and what that might do to the filter flow and motor.

any thoughts or opinions?

 

[DarkSoul]

1/4" is way to small for any real water flow.

 

[mellowvision]

well, is the 1/16th difference between the tubing specified and the barb going to make the difference, or is 3/8s also small?

 

[mellowvision]

er... I just did the math again, it's 1/8th difference, huh.

 

[Nolapete]

The problem with your thinking is that by reducing you are going to increase back pressure on the filter (BAD) and increase the velocity of the water coming out. To accomplish what you want to do, you need to go larger to reduce the output velocity. This won't change the amount of flow, but will reduce how forceful it is distributed within the tank.

 

[mellowvision]

yeah. I just can't find the parts I need to create disconnects (other than expensive eheim) for 3/8" tubing... I could probably use 1/2" tubing, but it's really loose on the filter barbs, and seems like a leak waiting to happen.

 

[mellowvision]

but on the intake side, wouldn't using larger tubing than specified make it harder to maintain the vacuum?

 

[TwoTankAmin]

Use hose clamps to secure tubing to the barbed nipple.

 

[Nolapete]

Two suggestions:

Since you are making a paludarium, how about making your own RUGF in the water section and running the output of the canister to power it.

or

Make a shelf to sit behind your tank.
Get a container that holds a quart to half gallon of water.
Cut a hole in the side near the top that you can use a threaded 1" pvc coupling and 90 to make a return that goes over the side of the tank. Get a rubber gasket and plastic washer to put on either side to make your own DIY bulkhead.
Either plumb the return from the canister into the container or just use a U tube and hang it over the edge.

Inside the tank, make some rockwork to break the falling water up a bit. You can have it falling into the water section for great aeration and waterfall effect.

 

[Nolapete]

Oops I thought we were still talking about reducing the flow rate. Guess that's what not getting much sleep does.