[Samper]

I'm working on a new sump and one end of it already has a 1 3/4" hole cut into the bottom and I plan to put a 1" bulkhead in it to feed my return which I want to be external and is a mag 18. I plan on running a series of four baffles and incorporating a section in the middle to hold all my excess liverock. 3 of the baffles will be over under over and will seperate the skimmer/rock area and the last baffle which is an over will go to the return compartment which I have figured needs to be a 9" space between the last baffle and the side wall of the sump. The sump will be elevated onto 6 4X4 blocks to allow me to plumb the bulkhead to the ball valve and then on to the return pump. What is the best way to plumb the inside of the return compartment...? I'm not sure that drawing straight off of the bottom is the best idea...maybe raise it a few inches and fit two 90 degree elbows together so that I'm drawing low...but not from the direct bottom. What do you guys think?

[Reefland]

If I read this correctly, I think one 90, attached to the bulkhead which is in the bottom of the tank will work fine.

[Samper]

Ok now for the bigger question. The back of the tank is going to be drilled four times. The 1.5" return line from the mag 18 will split into four 1/2" lines running straight to the back of the tank and four 1/2" bulkheads. I plan to drill these holes spaced 6" apart and about 4" below the bottom of the plastic lip surrounding the upper edge of the aquarium back. I plan to use slip/thread bulkheads and use locline for the outlets. I plan to angle the locline however I need to so that if the power cuts off I won't overflow the sump. I figure the locline will have to be angled up towards the water line then straight towards the front or sides depending on where I need flow. This should keep too much water from draining to the sump in case the power goes out. I thought about a closed loop but am not going to incorporate one at this time. Am I thinking about this correctly? Drawing this has proven to be difficult for me so I hope I got it across clearly.

[Reefland]

Yeah I think your on the right track. Perhaps instead of worrying about the backflow from the 4 outlets, you can consider putting a check valve in each line, and the case is closed. Or 1 check valve coming from the return, but before the split into 4 outlets.

Lastly, 4 outlets may be too much for the Mag 18 unless you are going to use a SQWD?

[Samper]

I have my plumbing split four ways now but two of the outlets empty much lower in the display and don't have the pressure that the upper two outlets have. I figured if I put the four holes evenly across the back glass the pressure would equalize between them. I have plenty of powerheads for extra flow but perhaps only two 1" holes/bulkheads and locline are needed....or since I'm running 1.5" pvc maybe it would be better to use two 3/4" bulkheads so that I'm still at the 1.5" total outlet size.

[Samper]

Aren't the check valves notorious for seizing up under reef tank parameters?

[Samper]

Is anyone else running the check valves and if I choose not to use one will my method of routing the locline towards the surface effectively keep too much water from back siphoning?

[Reefland]

That method will work, sure.

Check valves have come a long way, but here is the choice:
True Union Swing Check Valve - 1/2 inch Slip x 1/2 inch Slip (Saltwater Aquarium Supplies > Plumbing Parts > Valves > True Union Swing Check )
A union check valve.

[Samper]

Those prices are much better than the ones Premium Aquatics sells.

[Reefland]

Might even try around at plumbing supply places as they may be even cheaper. Maybe even usplastics.com.

[jsheffel]

If you do try it without the check valves, I would definitely test it while you are sitting there to turn the pump back on if the sump floods. Unless your sump is close to the size of your main tank, every 1/4 inch the main tank level has to go down before the siphon is broken is going to translate into much more in your sump. Also, are the joints of locline completely water tight?

[Samper]

I've always cut the power to test the sump but I've never plumbed one quite like this setup. Normally I run the plumbing up over the back glass and then down into the tank. I then drill small 1/4" or less holes in the back of the pvc and I angle them down so that the water doesn't shoot out once the pump is fired up. These holes usually go 1" or less below the water line and break siphon very quick and easy. Never had a problem. I think that the locline joints are water tight but someone else might chime in and correct me.