I have a few questions in regards to plumbing. I'm having a hard time grasping the concept of how to size the pump correctly along with the right size of pipe. Here is what I have planned and maybe someone can help ease my mind a bit.

29g display tank
10g refugium
PVC Pipe (Ø is probably going to be 1"-1 1/2")

I know that I’m going to need a pump in the fuge that can handle a 50”+ head. My main question is how do you plumb the intake so that it will break the siphon if you loose power to the pump? I'm leaning towards drilling the tank for a bulkhead but not sure how to break the siphon.

The other question that I had is, how do you ensure that your intake can keep up with the pump? And how do you ensure that the pump can keep up with the intake? I don’t want to flood my living room if one can’t keep up.

Here are some jpegs of my design so far. I haven’t selected a pump yet so it’s not in the diagram yet. The intake is on the left and the return comes back to a spray bar. Any help with this would be appreciated.



Thanks

OK...first, you don't really need a bubble trap on the front end of the fuge. it'll take up more space than you have (trust me, i've built several 10 gal fuges).

don't worry about having too much outflow for the pump. the pump determines the flow from the tank. as long as the siphon breaks on your return and outflow lines, the fuge won't overflow.

you can drill siphon break holes in your intake/outflow fittings so they sit about 1/4" to 1/2" below the water surface. these will break the siphon in the event of a power failure or if you need to stop the pump.

a single overflow will run about 300 gph, so your pump should be sized with that in mind. remember to take head loss into consideration.

Well your question seems a little vague to me, but I’ll give it a shot. You’ll have 39+ gallons in your setup lets round that to 40 to err on the side of caution and go from there. First thing, you want to circulate a min of 10 to 20 xs per hour. Let’s go with 20 because you can decrease you GPH with a ball valve but getting it higher means a new pump (been there done that). You’ll want about a 800gph pump you can add a power head to up your water movement. But I digress.

Let’s start with the 800gph pump. If you are pushing 800 GPH through your system you will be moving 13.3 GPM through your pipe which coincidentally is the max GPM for 1” schedule 40 PVC pipe. So we know that you’ll need a min of 1” pipe

Now lets look at you diagram and figure out you head feet. Here are some lines for the pipe fitters manual.

A. First, find the equivalent loss from each joint. These numbers are in equivalent foot lengths of straight pipe.

1" pipe: 90 bend 3', 45 bend 2', T-thru 3', T-bend 3', valve 1'.

B. Add up the total equivalent feet from all the joints and the total length of pipe.

C. Look up the right value from this list.
The numbers are for 0.75", 1', 1.25", 1.5", 2", 2.5", 3" pipe
0300 gph: 6.3, 1.9, 0.5, 0.3, xx, xx, xx
0600 gph: 23.1, 6.5, 1.8, 0.8, 0.1, xx
0800 gph: 48.3, 21.9, 4.0, 1.9, .25, xx
1200 gph: 73.5, 22.8, 6.2, 3.0, 0.8, 0.4, 0.1

D. To find the losses in lift equivalent, look up the right value from the table and then compute B x C/100.

E. Add D to waterfall and/or stream height to get the total lift (head) equivalent drag on the pump

F. Look at the performance table from the pump instructions to see the amount of water that will be delivered at the head computed in step f.

G. Repeat a-f for each pipe size under consideration. A preliminary c check is to see the pipe size where the high numbers for your pump size suddenly go low. Also compute the materials cost for each pipe size!

On your diagram you have 5 90° bends at 3’ each = 15’ head. Now the height of the tank is the question I’m going to take a guess and say 4’ with the spray bar and the bends lets add 2’ so that’s 6’ of pipe and 15’ of drag that make it 21’ of head.

So: 21X21.9/100=4.7523 head feet.
Now we have the pump size and pipe size. Now for the return from tank to sump if you don’t want to drill (I don’t) I use an overflow box they are all rated by GPH so just pick the appropriate size. Now for the return for sump to tank if you are using a spray bar that is above the water line it wont create a siphon in a pump failure. If it’s below the water line just drill a small hole .15” about .25” above the water line and angle it downward toward the tank. It will constantly shoot a small stream of water but in the case of a pump failure it’ll allow air in and break the siphon.

The only thing is in the case of a pump failure making sure your sump doesn’t overflow from the head in the tank. The best way I find to do this is outside fill the tank and get the overflow going then stop the hose. This is where the water line will be at failure. Fill your sump a little at a time from the hose till everything runs fine but has barley enough water to do so and you have a flowing system. Then kill the hose and pump and let everything drain into the sump. This is your min line this is the minimum amount of water you can have in your sump. Now fill you sump to about 1” of the top and start the system again when the water levels out mark that line as your max line if while your system is running the waterline goes much above that line you will have a wet living room.

Hope this helps.

Thanks Greg. That eases my mind quite a bit. I'm pretty sure what direction that I'm going to head now. I just have a couple more questions (more like scenarios).

So the power drops and my pump stops, thus causing my outflow to loose siphon. Is there a way to keep the pump from running dry when the power comes back online? This is assuming that the outflow isn't coming through a bulkhead and rather a 90° pipe from the top. It sounds almost like I would need a relay on the motor to keep it from turning back on.

Thanks PreauxPhoto for the in-depth sizing. It will come in handy.

aahhhh.... i see you dont have an overflow setup you are running a gravity fed siphon. there lies your problem! an overflow box creates 2 pools on the inside and the outside of the tank where the siphon tube between them never catches air so no matter how many time your pump stops and restarts the water will always resume flow.

check out this article i hope it will shed some light on the subject
Overflow Skimmers (http://www.thekrib.com/Filters/overflow-skimmer.html#0)

and here are some to look at while reading the article to get an idea.
Overflow Box - Marine Depot - Marine and Reef Aquarium Super Store (http://www.marinedepot.com/aquarium_overflow_boxes_cpr.asp?CartId=&adsite=google)

if you are handy with acrillic check this out
DIY Overflow Box (http://www.melevsreef.com/acrylics/overflow.html)

if you still need some help (as i did) go to your LFS and see if they have any setup or i'm sure they will demonstrate one for you.

Thanks for the links. They have helped a ton. I'm looking at the Mag 7 pump.
Danner Supreme Mag-Drive Aquarium Water Pump/Powerhead - Marine Depot - Marine and Reef Aquarium Super Store (http://www.marinedepot.com/aquarium_powerheads_pumps_danner_mag_drive_supreme .asp?CartId=)

Your calculations were pretty close to what I had calculated for head pressure. I'll probably build my own overflow, assuming I can find someone local that sells acrylic and my wife doesn't shoot me first...lol

i'd spend the extra $15 and get the 9.5 with that little cost diffrence bigger is better.

now that you mention it, the 9.5 does look a lot better. It will allow me to move my Magnum HOT filter to the fuge. Thanks for all of your help. BTW...i'll have about 1psi (dynamic pressure) on the PVC pipe.

well on 1" pipe max pressure is 370 PSI excluding craftsmanship at joints, i dont think toy will have to worry about it. with the 9.5 @ 4' head you will be right around 800 GPH (see link). i think you are well on you way. though belive it or not it's not that complicated, i've never had to do any calculations on building a setup most of us do it with simple math and feel. give it 6 months and you'll see what i mean.

PARTS LIST AND SPECIFICATIONS FOR MAGNETIC-DRIVE 24/36 AND PONDMASTER 24/36 PUMPS (http://www.dannermfg.com/InstructionSheets/MagneticDrive9.5-12-18Pumps.htm)

After all of the reading and understanding how this works, here is going to be my final design.

you might want to rotate your sump 180° otherwise you will have an uphill battle with top off you want the area with the most water volume to be where your pump is and put your skimmer in the smaller area with the constant water level & volume. also duplicate the box on the back of the tank bring it to the inside drop it about 1" and add filter slits about .2 wide .75 tall this will act as a prefilter otherwise you will be sicking fish into you sump every day.

I was planning on installing the pvc screens from Marine Depot on the overflow intake so I don't suck up any live stock. I was using the baffles to keep sand and other debris from being sucked into the pump. Is there a better way, other than just getting a prefilter, to keep junk from being sucked through the pump?

here is the way i set mine up on my 35 gal quarintine. i also have a ATO (not shown) feeding from a 10gal that i put RO/DI for both my 75gal and the 35 use the same 10 gal for there top-offs. without the ATO i had to top it off 2x a day, not bad but a pain in the.........

WOW! Leave it to a guy from Huntsville to give an explanation worthy of a rocket scientist! :eek:

All kidding aside, great explanation and very informative...

Thanks Bernie

Wow Preux! That was a great explanation.