Flow vs. Pressure

[NewSaltyReefer]

Caution!! Long explaination coming!!

I have seen so many topics about flow and how much is recomended for the type of tank you have. However I have not seen a topic about about pressure!!

What I mean is that, I have a 780GPH pump on my closed loop SCWD (about 500GPH with head and SCWD loss) and a HOB Skilter which puts out 250GPH. So I have anywhere between 750-900GPH on my 20H.

From what I have read, this is a good amount of flow for my tank, however things do not seem to be moving around as well as I thought they would. So, I covered half of my 3/4" LockLine outputs with my fingers, increasing the pressure, and I really started to see some flow!!

Is the higher pressure important or is it JUST THE FLOW? Should I switch to 1/2" LockLine? Is the SCWD my biggest problem? Please HELP?!?!

Melev's SCWD setup seems to put out so much more power than mine:mad2:

Here is a pic of the LockLine SCWD setup:

 

[Agu]

It depends on what you want to keep in your tank.

In my LPS tank I have a lot of water movement but it's deflected to prevent intense flow from hitting the corals. If the same tank had SPS I'd want more intense flow hitting the corals.

From the pics I can't see what type of nozzles you have on the locline. Different nozzles create different flow as you've discovered. Perhaps changing the flow/pressure would be as easy as changing or modifying the nozzle.

 

[MiddletonMark]

What kind of pump are you running?

Some do better at pushing against plumbing/etc on the other end - some do not as well IMO.

 

[NewSaltyReefer]

It is a QuietOne 3000

 

[BurntOutReefer]

isnt the max on a SCWD 895G's...? Thought I read that somewhere....your are also losing (this sounds like a XRated chat) head using the outlets (forgot what they are called)....
so....do you want gentle or hurrican flow?
step down to a smaller outlet for more force....go up for gentle...IMO

 

[sjm817]

SWCDs are a flow killer, especially on a pump that is not a pressure pump.

 

[Scuba_Dave]

Do you have a nozzle on the end of the locline?

 

[NewSaltyReefer]

Yeah I do have that nozzle!

And is gentle flow okay or do I want more force...I have no idea what is better!! I want to keep SPS.