How much....

B

bonafied

How much water can a 1 1/2" bulkhead drain?

I have a mag 9.5 and am thinking about going for a mag 24. Will my drain handle this? Can I back it down?
 
Go to http://reefcentral.com/ and look at bottom left under calculators. First figure out the "head loss" then go to " drain/overflow size." I would always use a ball valve on the return.

MBZ
 
I had a 1" drain on my 75 and had to dial back my mag 7 a bit so I am guessing a mag 24 is a little overkill. The mag 9 should be plenty.
 
On my tank I have 2 1" drains from the corners. My return is mag 18. My return has 2ball valves and 2 check valves(1 in each return) in the line. The ball valves are wide open. I have no problems with the drain. I do believe a single 1" drain can not keep up with a mag 24.
 
Right now I have my mag hooked up and have no problems with my drain...I drilled a hole in the top because of the tolit flushing sound..if I make this hole smaller or eliminate it altogeather...wouldn't it drain faster?

By the way...I believe I made a mistake about the size of the drain...I believe it to be 1 1/2".
 
I have a hang on overflow with dual U-tubes but only a single 1-1/4" drain.

My mag 7 is almost too much flow. I have it dialed back to about 80%.


I would think a mag 9 would be way too much unless you have at least 2 x 2".


BD
 
Assuming your bulkhead opening given is inner diameter, the 1.5" bulkhead would have the following drain rates (height in inches is the distance between the top of the pipe leading to the bulkhead and the water level, normally 2-3" with a durso pipe)

Height / Approximate Flow Rate
0.5" 400 gal/hr
1.0 600 gal/hr
2.0 850 gal/hr
6.0 1600 gal/hr

Since the mag9.5 returns water at about 800gph @ 4' line, you should be good... Mag24 at around 2000gph is going to be serious overkill. What size is the main tank? Turnover recommended by our expert members was 5x water volume of tank per hour.
 
Tank Length = 60 inches
Tank Width = 18 inches
Tank Height = 20 inches

Show Tank volume is calculated as
Tank Volume = 93.5 Gallons
So, I SHOULD be turning 3,740 gallons per hour. (40x93.5)

As stated.. bulkhead is 1 1/2"

It IS a Durso Standpipe type..and water level is 2-3 in. from top of pipe. Drain and Overflow sizes are calculated as
Recommended minimum drain pipe diameter = 2.53 inches
Recommended minimum linear overflow size = 56 inches



Mag 9.5 with various elbows,couplings, & 45's (restricting flow) and 3 ball valves = Total losses are 9.74 feet of head pressure, or 4.21 PSI. with a flow rate of 434 GPH. (and that's with a pipe diameter of 3/4in. - STUPID me, I used 1/2in pipe!) :shock:

So, How to get approx. 3,300gph! :? :? :shock:
 
I have a 115/120 depending that has 2 1" drains and a 2" return. The overall drop/Lift is 52" and if I run a Mag 18 it's severely overpowering.
I run with a Laguna 1500 and a pair of Seio 820's for circulation. my overflow noise is low but it still gurgles when I do an intank topoff.
you may want to look at a quiet one 4000HH or if you can find a Laguna 1500 grab that. For additional intank flow, you can go with powerheads or a closed loop system. The closed loops system can run independantly of the return pump which is great for feedings.
If you want to go with a much larger pump, you also have the option of splitting it off on the outlet to power a skimmer.
 
I am thinking of doing some reading on the closed loop system. As I am trying to avoid the powerheads in the show tank.

I can drill the holes for it myself, as I drilled the hole for the Bulkhead for the drain. Then again, I could just add another drain at the other end of the aquarium. But that would mean another overflow, taking up space and making it harder to make the total mass of water circulate.

I am liking the closed loop more and more.

Now for the question:

How big should a pump for a closed loop be?
 
If you have a 1.5" durso draining into a 1.5" bulkhead, that can handle about 1500gph. You don't need it to drain that fast though. That is just its maximum rating. If you use a large pump, you may slingshot microbubbles through the sump and back into the display. Most people don't like the look of microbubbles in their reef tank.

For a closed loop, you can have as much flow as you like, because normally microbubbles aren't an issue. There is a caveat though: If the plumbing is too small from the tank to the intake of the closed loop pump, the impellar may cavitate and create bubbles which would then be pumped back into the display. So make sure the plumbing diameter matches the pump's GPH.
 
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