Quick question on materials for sump plumbing- Please, Need help!

[reefstarter]

So I am restarting a 70g reef tank (had to dissemble when I went away for a year), and I have built for it a 20g refugium/skimming sump, as seen in the picture attached.

I have an overflow box behind it, and plan to run (ideally semi-flexible) tubing down the back and into the left hand side of the sump, and then from the right hand side of the sump back up to the aquarium. I am a novice when it comes to DIY stuff, however, and don't know what tubing or attaching materials to use. Cheaper is better, and easier to put together is better. What are your suggestions? Please be specific enough that even I understand. Thank you! My return pump is a King 225 pump with a 1/2" diameter output, and the bottom of my overflow is 3/2" diameter.

 

[AZDesertRat]

If the over flow box is 1/2" I would use a 1/2" barbed nipple off the overflow box with 1/2" inside diameter heavy wall or reinforced clear vinyl tubing like found at Lowes or Home Depot. You may be able to find black vinyl tubing which is nice since it cuts down light transmission and algae growth in the tubing. You had a typo saying 3/2" so possibly you meant 3/4" in which case I would use 3/4" for the barbed nipple and tubing.

Since the pump discharge outlet is 1/2" I would attach a 1/2" ball valve to the pump outlet then a 1/2" barbed nipple and again reinforced or heavy wall vinyl tubing back up to the display. If you don't have a return outlet you can make something up with two or three 90 degree elbows so it hangs on the side of the tank and shhots back down or horizontally into the tank. They also make black plastic retuen sweeps you can find at a LFS which look nice and are not too expensive. Just don't let it extend too far down into the display or the system will drain to that point in a power outage, I like to keep my returns 3/4" to 1" below the surface so only that small amount of water siphons back before the return is exposed to atmosphere and the siphon breaks via an air gap, the best form of backflow prevention known to man.

 

[reefstarter]

Thanks for the help! The 3/2" actually wasn't a typo. The drain from the overflow box is One and one-half inches wide. What should I do with this?

 

[AZDesertRat]

Is that the inside diameter of the bulkhead or the outside? You cannot attach to the exterior threads since they are not a standard tapered pipe thread and will not seal. it is the inside diameter and most are 3/4" or 1" in that size HOB overflow. I would take the bulkhead to Lowes or Home Depot and match something up unless you have some PVC pipe and fittings laying around. Is the bulkhead slip or threaded on the inside?

You might find some use out of this sticky post:
https://www.reef2reef.com/forums/eq...iltration/34973-installing-bulkhead-tips.html