head loss calcu

[fishguyxd]

I have tryed two of them using same numbers and get diff answers
I use 6 ft for length and a mag9 pump as my example no unions or valves yet. I get 7.16 head pressure and flow rate of 635 gph at reefshow site and at reef centrel site i get 7.84 head pres. and 587 gph so I was told i need about 10X tank cir per hr.for good flow so i would need 720 correct for a 72 gal tank could someone tell me if this is correct or what i do need other than more reserchand experience if i use a mag 18 is that to much flow or should i use like a mag 12 or rio 20hf.to get the right numbers

[Invigor]

i have a mag 12 on my 105g, plus a 270gph powerhead

[monza]

What are you keeping or planing to keep? SPS you can and should have way more flow.

Dave

[StirCrazy]

What are you keeping or planing to keep? SPS you can and should have way more flow.

Dave

this is true but that flow doesent have to come from the return pump.

Steve

[Vagabond]

I use a Mag 12 for a return on my 60 gal. with slightly more head loss than you are calculating with. I also have 2 Aquaglobe mini powerheads pushing 300gph each. Corals and fish are all very happy :biggrin: .

I would probably go with a Mag 12 or even an 18 on your 72 depending on how many return outlets you want from the pump.

HTH

[hockey nut]

I'm not an expert , but from what I've read and have been told from various people, you only need to have your tank cycle about 5-7 times per hour to ensure good water quality. If your water is moving through your sump too fast it may not get proper contact time with the skimmer , heater and whatever else you may have to filter or scrub etc. It realy depends on what type of tank you are setting up. I personally can't see why 10 times would hurt but you may be just wasting your money when the pump you have now would be fine . Maybe somone will post a more accurate statement. HTH

Cheers

[Buccaneer]

The amount of flow sometimes is not as important as even flow ... what I mean is you can get 5 to 10 times water turnover per hour through your sump if you like ( although 3 to 4 times per hour would probably suffice ) ... but more importantly is to get circulation throughout the tank ( either with extra powerheads or closed loops ) and avoid " dead spots " where detritus can accumulate unnoticed ... I think this is the problem area we run into that causes water quality issues.

So the bottom line is if you have SPS ... get 3 to 4 times per hour through the sump ( any more than that and you may run into overflow not being able to handle the volume and more contact time for skimmers / heaters etc )

And then another 7 or more times per hour from closed loops or powerheads

HTH