over flow ?

[bigbill]

i had a 1 1/2 inch drain drilled in my 80 gallon tank do i need to put an overflow box around it our can i leave just the drain and if i need a box how far from the top of the drain should it be

http://i701.photobucket.com/albums/ww15/bigbill_01/IMG_2205.jpg

[shovelhead91701]

unless you want a lot of fish etc. to make a trip to the sump I would recommend an overflow box with "teeth" at the top to help keep smaller fish from getting pulled over the top with the flow. build your standpipe to be as tall as the overflow box( height of overflow box dictates the water level maintained in the tank) with your return elbow about 4-6 inches lower than the top of the standpipe. Also do not glue in the standpipe to the bulkhead, that way you can remove it to clean the overflow area from time to time.

Here is a great thread to explain the standpipe construction in detail.........
http://www.captivereefs.com/forum/showthread.php?t=3730&highlight=overflow

[XSiVE]

put an overflow box around it and have the top of that be where you want the water level to be..

put a downward facing elbow on the inside of the tank, and put a capped Tee on the outside of the bulkhead (with a hole drilled in the cap) and you've got a nice external durso style overflow.

[bigbill]

ty shovelhead how big of pipe should i use for a 1 1/2 inch drain

[XSiVE]

This is drilled in the back near the top, right?

[bigbill]

Back left top corner

[shovelhead91701]

i thought it was drilled in the bottom...sry bill. Just use a tee with the cap like the other style but let the "bottom" of the tee be the "drain". the top of the tee with cap to vent and control flow rate via the drilled hole in it. and the third port of the tee put a stub of pipe into it to go to your bulkhead. Use whatever size pipe your bulkhead is sized for.