Hypothetical reef tank

[mr_alberta]

My tank was BB so no worries about the sandbed. The longest length was 45" with a 14" segment at the end (it was L-shaped). It wasn't a true calfo manifold as it wasn't all one continuous "loop". I split the manifold in half with a SCWD so that only half of the "loop" would fire at a time. Worked quite well, but too bad the SCWD adds so much headloss to a pump. In retrospect, an Ocean Motion 2 way would have been better as you can use much larger pumps with it.

[christyf5]

Uh, pardon my ignorance, but do you have to provide an "excess" of flow so that water makes it through to the final outlet at the end of the line (so that you don't have the most pressure coming out the first outlet, then less at the second, even less at the third etc?).

[michika]

Originally Posted by christyf5

Uh, pardon my ignorance, but do you have to provide an "excess" of flow so that water makes it through to the final outlet at the end of the line (so that you don't have the most pressure coming out the first outlet, then less at the second, even less at the third etc?).

Good question...I'm pretty ignorant too about this....anyone?

[Der_Iron_Chef]

Couldn't you add ball valves to all the returns, and dial the ones closest to the return more closed, with the ones at the end fully open? Tweak until you get even flow? I've also wondered about this, and it's the only solution I can work my mind around.

[christyf5]

Originally Posted by Der_Iron_Chef

Couldn't you add ball valves (or whatever they're called) to all the returns, and dial the ones closest to the return more closed, with the ones at the end fully open? Tweak until you get even flow? I've also wondered about this, and it's the only solution I can work my mind around.

Thats what I was thinking as well. However of every photo I've seen, nobody has used ball valves or anything, they all look like Harveys setup.

[danny zubot]

No ball ball valves required if you use a pressure rated pump.

[Der_Iron_Chef]

Originally Posted by danny zubot

No ball ball valves required if you use a pressure rated pump.

Hey Danny, can you explain this? I'm a pressure rated pump dummy

[mr_alberta]

There's got to be a Mech. Engineer somewhere here that can explain why you don't need ball valves on a closed system like a Calfo Manifold...

Originally Posted by christyf5

Uh, pardon my ignorance, but do you have to provide an "excess" of flow so that water makes it through to the final outlet at the end of the line (so that you don't have the most pressure coming out the first outlet, then less at the second, even less at the third etc?).

[christyf5]

OK here is my theory, you shoot water through the pipes so fast that only some gets split off to any given tee. The rest of it is propelled super fast on to the next tee because it doesn't have time to make turns at the tee. However at the end tee either there is just the right amount of water that comes out or you could launch mysis from it at the speed of light!

[danny zubot]

I'm not an engineer but here's what I figured. If you have a 1" return but only use 3/4" output holes, it will create back pressure on the main line. This, in theory, should pressure up the main line enough to have even flow out of all holes. Kind of like those long irragtion hoses with all of the tiny holes in them. A pressure rated pump will keep the line pressured better than a none-pressure rated pump.