Overflow Sump Return Questions

[DOGMAI]

So I finished filling the 120 last night. It was a little hair raising because I have never had a tank with overflows and a sump. I had to make sure that I did not put too much water in so that I did not flood the sump when I turned off the pump. One thing that I found real quick was that you cant have your outlets too deep under the surface of the water because it will back siphon when the pump is shut off. Is there a way around this? What If I want to have the returns point down towards the bottom of the tank? I have never seen this discussed before so I was just wondering.

Also found out that two one inch returns plumbed together to a one inch pipe cant keep up with an Iwaki WMD30RLXT. I had to run each return in a separate line to the sump. Can I plumb the two together into a 2” line?

Also when the water dumps into the sump it creates a lot of bubbles. Is this normal?

Thanks for any replys. As I said I am new to this overflow return setup so any advice will be helpful.

Thanks,
Shane

 

[Anonymous]

You can drill 3/16" holes just below the water surface in the pipe. Sucks air, siphon breaks. Just make sure to keep the holes clear of algae.

"Return" usually refers to the pipes going from the sump back up to the tank via a pump. I think what you're referring to in your 2nd paragraph is your overflow drains, yeah? Yes, if you have them meet at a 2" tee by using reducers you should be fine. Actually you can probably get away with a 1.5" tee as well. A 2" pipe can actually drain 4 times as much volume as a 1" pipe. A 1.5" pipe can drain 2.25 times as much.

The bubbles are normal. There are several different ways to reduce them so they don't get pumped back into the main display.

 

[DOGMAI]

Your right I meant drains. Sorry.

Shane

 

[J.Howard]

It's always a good idea to install a flapper style check valve in the return line. Make sure it's not a spring loaded type as they create too much back pressure, not to mention made of metal. This will keep more water in the tank where your animals really need it in a power outage. Your LFS will have the correct type especially if they do maintenance or installs. Go up in size for the inlet/outlet of the check valve as well...ex. if your returns are are 1" get a 1 1/2" etc. I have this set-up on both my 180 and my 20 and they work every time. Test your system to simulate a loss of power from time to time to insure that you are in good shape when the real thing happens. You know it never goes out when you are home. :x

 

[Anonymous]

Check valves have a notorious reputation for clogging and not working right in a power outage. Sponges, tubeworms, etc grow on the hinge over a few months and then you're screwed.

 

[J.Howard]

Thats why I said to check it regularly. Holes in the return do the same thing, so what's the difference?

 

[J.Howard]

BTW I'd like to add that this method has worked for me for years. Don't see many sponges or tubeworms that like to live in a constant, concentrated flow 0f 800-1300 gph. I'm not a moderator, just a regular reefer, but I don't think it's a hobby standard to only use the method you describe, so why bash mine?

 

[DOGMAI]

I had sponges and gastropods living im my skimmer where the water flow was constant and quite fast. I do think they would live in a return pipe and even a drain pipe with no problems at all.

I thought about check valves and things of that sort but would only use those if i could get electronic ones that automatically closed in a power outage.

Thanks,
Shane

 

[DK]

I use both, the drilled holes and the valve and have had them for several years. I have had nothing to impede the check valve and it is a good backup to the holes. The sponges in my euroreef skimmer virtually cover the inside of the lower chamber but that flow is considerably less than the flow through the return line. In my ETSS skimmer, nothing but limpets can survive that flow. So, I support J Howard's assertions.

 

[J.Howard]

Thanks DK! Was thinking I was a loner on this one. :mrgreen: