Head loss Calculator

[Indigoblue12]

Wanted to know what you guys think
About the figure I received when i calculated my
Head loss ...

I have an old Rio 3100 pump and it calculated
567GPH
So I started looking at a pump called a MAG 9
To purchase but it still comes up 642GPH

I like how I'm running my return and it looks good.
Yes I have one 45 and two 90s and about 5
Foot stretch to top and a 4 foot vertical run.

I'm running a Herbie with 2 drains

 

[wolfblue]

When you ask a question like this you need to list pipe sizes. I cant tell if your 3/4 or 1 inch and I'm a little confused about "to top" vs. "vertical". One inch is much better for this pump and 1.25" doesn't help much. But 3/4 inch adds a good bit of head around these GPH. I bet your 3/4" which is OK if you don't want too much flow. But you'll be wasting a small amount of electricity if you throttle a somewhat oversized pump with somewhat undersized plumbing.

This is the pump curve the head loss calculator uses. You have calculated 7' of head which is 3 PSI. Head and PSI is the same thing, 2.31 feet= 1 PSI. A pump curve tells you how much flow you will have if you have a certain pressure. If you put a pressure gauge on the output of the pump and then a valve, and set 3 PSI with the valve the pump will be doing 650GPH according to the curve. So you have 4-5 foot vertical and the rest of the head pressure is from the restrictions and friction from the plumbing.

If you want to get back down to 575ish on the curve you have to add 1 more foot of head to be at 8', add 0.46PSI. Do that by adding a valve after the pump and close it partially. But you might find you like more flow if Herbie can take it.

 

[Indigoblue12]

This is a picture of my line
View attachment 288947


I have not ran the line yet so I can use
3/4 or 1" I assume. I plan to run the line
Behind the overflow box so I have no
Nasty PVC pipe showing ...
What I don't get though is that I would
Think the putting a return next to the overflow
Box would be a crap idea because your prob
Just sucking in the water you just ran through
Your sump...
One would think you would get better filtration
With return line placed on opposite end of the drains and

 

[Indigoblue12]

Maybe I'll run the line then straight up the back
Although I'll have to get a black background
To hide the PVC pipe.

What is my flow rate supposed to be
On a 90 gallon tank?

 

[wolfblue]

What is my flow rate supposed to be
On a 90 gallon tank?

Opinions vary but most would say 3x-5x system volume. If your sump would hold 10 gallons, 300-500 GPH. So with 1" return line a Mag7 pump would do right at 400GPH. And about 360 with 3/4" lines. The difference between 3/4" and 1" is more with the Mag9 because resistance goes up as water velocity in the pipe goes up.

The truth is any thing from 2x-10x flow is good in a reef. But my opinion is that even down to 1.5x is OK. All of your filtration things would pull from, and then dump back to the sump. So your filtering the sump and the aquarium also pulls from, and dumps back to the sump. We used to use sump flow as part of the reef flow. But now people are running smaller return rates and pumps to save electricity. And using propeller pumps or power heads inside the reef tank for water flow that the corals need. These propeller pumps move massive amounts of water for low watts.

So I think you would be good to use a Mag5 with 3/4" and get about 210-220 GPH. And 230-240 GPH with 1". Danner Mag pumps are cheap but not very efficient. You might search RC for threads discussing more efficient pumps. If a $100 pump lasts 3 years but burns $180 more in juice in three years, the $200 pump is a better choice.

 

[wolfblue]

Think the putting a return next to the overflow
Box would be a crap idea because your prob
Just sucking in the water you just ran through
Your sump...
One would think you would get better filtration
With return line placed on opposite end of the drains and

Probably better to have it on the opposite end. But its jetting out of the return so it will not just recirculate 100% of the flow. And you can use power heads in the display tank to mix it in.