Overflow Plumbing Advice

aileen · Nov 4, 2017

ok, so I'm getting back in the game after a 4 year break and picked up this frag tank. 48x24x16. I built a stand and using a Rubbermaid sump to add volume.

The frag tank has two drains with no overflow box as you can see. The bulkheads are exposed in the tank with vent covers. They are 1 1/2 drains. There are two returns that are 3/4 inch. I'm used to have a overflow box with a Durso standpipe. Can I just plumb the drains to empty directly into the sump? I have a feeling the way this is setup will create a full siphon with lots of gurgling noises currently, am I wrong?

Thanks for the help in advance! Love this forum!

Mandelstam · Nov 4, 2017

I don't think neither of the drains will create a full siphon. Full siphons are dead quiet, no air in the pipes. For a drain that's open to air to be quiet it can only have enough flow to keep the water clinging to the sides of the pipe so the air will be one long column in the center of the pipe down to the sump. So I think you CAN get it quiet but it won't be at the flowrate you want probably. So yes, I think that setup will generate some noise. With an added overflow box you can make a herbie or beananimal style drain that will be quiet though.

Erica-Renee · Nov 4, 2017

Those Drains will either have to be very slow flow or will be very loud.. I would install a over flow box on each of them. At this point it would be very easy to do at this time..

aileen · Nov 4, 2017

This should work much better

Erica-Renee · Nov 5, 2017

There are many designs . This link might help you

https://www.google.com/search?q=ove...1#imgdii=np4A3lxR_RQ-BM:&imgrc=0neQojK_owbSbM:

aileen · Nov 5, 2017

Is an overflow box a must have? I'm just wondering why? I get it skims the top of the water column but any other reasons?

Mandelstam · Nov 5, 2017

They also keep critters and other loose things away from the strong suction at the opening of the drain pipe. The teeth divides the flow over a much larger area.

K. Steven · Nov 5, 2017

Put ball valves on your drains and tune them to a full siphon. Just periodically check your overflow screens to make sure they don't get clogged. These are essentially acting as overflow box teeth, keeping things out.

Erica-Renee · Nov 5, 2017

the over flow box is Almost a must... It regulates the water level of the tank , Ie overflows the amount of water back into the sump that your pump pushes up. It prevents the water from over flowing the top of the tank but keeps it at a level just below the top. You can do this with a pipe at the surface but its noisy

Engloid · Nov 5, 2017

Turn your inside strainer upwards and it will help skim the surface. Also...I wouldn't advise putting valves in if you only have siphon lines...because eventually, you will wind up overflowing the tank. I would only run a full siphon if you have a three pipe setup, with one being siphon, one being a secondary, and the third as an emergency. You could do it with two, but the third does add some safety.

aileen · Nov 5, 2017

Two drains plumbed separate and two returns plumbed together with a valve to slow the flow of I want. It's a 80g rimless I'm only going 700gph for return rate just under 10x per hour.

aileen · Nov 5, 2017

Backside

aileen · Nov 5, 2017

The caps on the drains are each drill with a 1/4 hole to prevent a siphon issue

aileen · Nov 5, 2017

Need to fill it up now and see if it works

Mandelstam · Nov 5, 2017

Keep us posted!

Erica-Renee · Nov 5, 2017

ohh if this tank is in your basement then you will be fine in the original picture with the screens . It will be loud and gurgle but no biggie down there