Overflow drain piping?? HELP!

conefree · 01/26/2006, 06:09 PM

Well I just finished plumbing my system here and decided to fire it up. I was somewhat confused by the results. I am running a Mag 12 pump thru 1.5" PVC, wyed to two 1.5" outlets. I have a Lifereef dual overflow (rated for 1400gph) with dual 1" flex PVC drains and dual stockman standpipes.

Here is the issue: My Mag 12 is overwhelming the overflow (overflow box level is not lower than tank level), which is pretty pathetic considering there is probably only about 950gph going through it.

I have tried two different drain setups:

1. Slow sloping lines to the sump
2. What looks like a 'drip loop' coming down below water level in the sump and then back up.

I am assuming that either one of these two configurations will reduce the flow of the overflow? I think that is why my pump is overwhelming it.

Would it be better if the 1" drain lines just had a straight vertical shot down to the sump? Will that increase my flow rate and also get rid of the surging and occasional huge burst of air bubbles in my sump?

I would appreciate any advice, I think the straight shot might be a solution, but I would like to hear some ideas before I go cutting my flex PVC and thus have to buy more if it doesn't work.

Thank you everybody!

conefree · 01/27/2006, 08:48 PM

I just uploaded two pictures to my gallery to help explain what I am talking about. Any help would be greatly appreciated. Thanks!!

unsane · 01/27/2006, 09:03 PM

I would "T" the overflows into 1.5 or 2". I also would run straight 3/4 from the Mag drive.

sjm817 · 01/27/2006, 10:05 PM

I'm not wild about the drain line setup. What kind of tubing is that? Why the loops?

Is the overflow keeping up? Does the tank level continue to rise and the sump drop? A tall standpipe like you are using will also cause the level in the skimmer box to rise. What happens without the Stockmans?

I'm not at all a fan of big return pumps and high sump flow...but...you are one of the few that actually correctly plumbed the Mag pump not to castrate the flow. Yes, 3/4" from the Mag would kill the flow. If you want to do that, use a smaller pump.

Fast Fred · 01/27/2006, 10:33 PM

If you'd like my somewhat educated guess, here it is: The drain lines are too small in diameter.

Think about it this way...

In your house, they use 1/2" copper pipe to feed your shower, but a 1.5" or 2" line for the drain. Why? Because the 1/2" line is pressurized and the 1.5" line is gravity fed. See the flow difference between the two?

You have a 1.5" supply, and (2) 1" drains. My guess is that the drains should be larger if you really desire that much flow through your sump.

I hope this made sense.

Mykayel · 01/28/2006, 01:10 AM

Is the water level in the overflow box (the one in the tank) rising above the bottom of the weir cuts? If so, then you are not getting enough water back to the sump... and the first thing I would do is get rid of that loop in your drain line.

Secondly, you might want to try choking off your return pump, it looks like you already have a ball valve. Choke it off and then slowly open it to see how close to its max volume you can achive without overwhelming the overflow. You might be right at that point of equilibrium but you have to shut it off before hand because it looks like you are going to just overflow yoru display.

01/26/2006, 06:09 PM	#1
conefree Gene Pool Lifeguard Join Date: Jan 2004 Location: Downingtown, PA Posts: 758	Overflow drain piping?? HELP! Well I just finished plumbing my system here and decided to fire it up. I was somewhat confused by the results. I am running a Mag 12 pump thru 1.5" PVC, wyed to two 1.5" outlets. I have a Lifereef dual overflow (rated for 1400gph) with dual 1" flex PVC drains and dual stockman standpipes. Here is the issue: My Mag 12 is overwhelming the overflow (overflow box level is not lower than tank level), which is pretty pathetic considering there is probably only about 950gph going through it. I have tried two different drain setups: 1. Slow sloping lines to the sump 2. What looks like a 'drip loop' coming down below water level in the sump and then back up. I am assuming that either one of these two configurations will reduce the flow of the overflow? I think that is why my pump is overwhelming it. Would it be better if the 1" drain lines just had a straight vertical shot down to the sump? Will that increase my flow rate and also get rid of the surging and occasional huge burst of air bubbles in my sump? I would appreciate any advice, I think the straight shot might be a solution, but I would like to hear some ideas before I go cutting my flex PVC and thus have to buy more if it doesn't work. Thank you everybody!

01/27/2006, 10:05 PM	#4
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	I'm not wild about the drain line setup. What kind of tubing is that? Why the loops? Is the overflow keeping up? Does the tank level continue to rise and the sump drop? A tall standpipe like you are using will also cause the level in the skimmer box to rise. What happens without the Stockmans? I'm not at all a fan of big return pumps and high sump flow...but...you are one of the few that actually correctly plumbed the Mag pump not to castrate the flow. Yes, 3/4" from the Mag would kill the flow. If you want to do that, use a smaller pump. __________________ - Scott

01/27/2006, 10:33 PM	#5
Fast Fred Registered Member Join Date: May 2004 Location: Northfield, NJ 08225 Posts: 1,170	If you'd like my somewhat educated guess, here it is: The drain lines are too small in diameter. Think about it this way... In your house, they use 1/2" copper pipe to feed your shower, but a 1.5" or 2" line for the drain. Why? Because the 1/2" line is pressurized and the 1.5" line is gravity fed. See the flow difference between the two? You have a 1.5" supply, and (2) 1" drains. My guess is that the drains should be larger if you really desire that much flow through your sump. I hope this made sense. __________________ Ya know, for a clown fish, you're not very funny! Member of the New Jersey Reefers Club Current Tank Info: 125g Reef Ready AGA /55g Top Fin Tank for a sump/refugium/ LifeReef Skimmer/ Changing over to SPS only

01/27/2006, 08:48 PM	#2
conefree Gene Pool Lifeguard Join Date: Jan 2004 Location: Downingtown, PA Posts: 758	I just uploaded two pictures to my gallery to help explain what I am talking about. Any help would be greatly appreciated. Thanks!!

01/27/2006, 09:03 PM	#3
unsane Registered Member Join Date: Jul 2004 Location: Indiana Posts: 217	I would "T" the overflows into 1.5 or 2". I also would run straight 3/4 from the Mag drive.

01/28/2006, 01:10 AM	#6
Mykayel Registered Member Join Date: Jun 2005 Location: Kansas City, MO Posts: 586	Is the water level in the overflow box (the one in the tank) rising above the bottom of the weir cuts? If so, then you are not getting enough water back to the sump... and the first thing I would do is get rid of that loop in your drain line. Secondly, you might want to try choking off your return pump, it looks like you already have a ball valve. Choke it off and then slowly open it to see how close to its max volume you can achive without overwhelming the overflow. You might be right at that point of equilibrium but you have to shut it off before hand because it looks like you are going to just overflow yoru display.