Periscope drain

Homer Allman · Jul 25, 2015

I've read and looked a lot over the past month about tank plumbing. There are a lot of good ideas and pictures out there but I wanted something different. I've never saw anyone using this set up, maybe I just missed it. Maybe i'm the first. Let me explain how I think it's going to work and please share your thoughts. I want to have my drains to be lower on the back of the tank. I want to create the ultimate flow while remaining mostly stealth. I do not want an overflow box. I do not want a corner overflow with a cover. I want stealthy.

I will drill my drain hole 12 inches down from the top of the tank , this drain will go into the refugium. I will install a bulkhead, 2" in this case, and 2" strainer. The flat round type. The bulkhead will be connected to the "periscope drain", as pictured below and as I call it. The pipe will all be on the back of the tank, unseen. As the water level rises in the tank the water will work it's way into the strainer and start up the back in the periscope until it reaches the top and starts it trip to the refugium. The "PD" fittings on top will be even with the top of the tank in the back. This means the water will stop draining at approximately 2 inches from the top of the tank. I will add some gate valves lower on the piping to set the water level and flow where I want it.

Do you guys see any problems with the periscope drain working or do you need a better explanation of how it works?

DaveMorris · Jul 26, 2015

It will drain water, but it will act as a siphon and drain the water from where the intake hole is. You would need to come up with a way to keep it from draining your tank when your return pump is shut off. If you think about it, it would act exactly like a hose would when you siphon water out of your tank up and over the top.

Homer Allman · Jul 26, 2015

It won't drain the tank. The water level can only go down as far as the two elbows allow at the top. Once the water level gets below that turn at the top it can't drain anymore. The water will rise to the elbows and once below it will stop or at least it should. I will test it just too make sure, but I sure it will work and stop draining once it get below the elbows.

steve&mari · Jul 26, 2015

The down side is it won't skim the surface so may cause a film build up on water surface.

Homer Allman · Jul 26, 2015

Steve & Mari I agree. This is why I'm going to build in massive flow.

This water will be turned over a lot, so hopefully there will be no time for anything settling on the top.

Windy · Jul 26, 2015

What is massive?

Homer Allman · Jul 26, 2015

Two pumps at least 4000 gph. One on the open refugium loop the other on a closed loop. 2 Ecotech MP60's or 4 MP40's. It's a 300 gallon with 125 gallon refugium. It's going to need some water movement.

ReeferEric · Jul 26, 2015

i couldn't comprehend anything you wanted to do. Maybe sketch it up?

Windy · Jul 26, 2015

Maybe if you explained your plan and what you intend to keep in the tank, we could be more helpful. Right now, I am confused as to what you intend.

Homer Allman · Jul 26, 2015

I will try and take some more pictures this week to better explain. I told you fellow reefers, I've never saw one like it and it's so simple.

Homer Allman · Jul 26, 2015

I'm just setting up the tank. I have a long ways to go though and I am trying to get a plan in place before I mess up. I would like to do a SPS dominate tank with live rock and a sand bed. The tank is 300 gallons.

Homer Allman · Jul 26, 2015

Ok I hope this picture can clear things up a bit. The drain is pictured with me holding it on the front of the tank. Once finished the drain will be on the back of the tank and not seen. The picture shows the approximate location and flow of the water. I'm still not sure on the exact length, meaning how deep will the drains go. The picture is close.

Homer Allman · Jul 26, 2015

DaveMorris · Jul 26, 2015

If you are saying that the water level will only go to just above the horizontal part of the pipe, then yes I understand what you are saying. Unless you use something like 1.5" or 2" pipe, you still run the risk of developing a siphon and emptying your tank down to the intake.

Homer Allman · Jul 26, 2015

Those are 2 inch pipes, so they should not ever run full. Yes I have the water level marked with tape and a black line. I just do not see it siphoning. I will test before I drill my tank.

zesty · Jul 27, 2015

Let us know how the test works out.

Windy · Jul 27, 2015

What I don't understand is why use a siphon drain? Overflow boxes use them and they work but occasionally fail, especially on a power outage. I also don't see any reason to drill the tank. Your siphon is higher than the side of the tank, so just drop it inside and you have the same drain.

Homer Allman · Jul 27, 2015

Windy I just do not want to see any plumping inside my tank. The tank is acrylic so drilling is not a problem. Hanging my current periscope inside the tank would not drain anything in it's current configuration. The overflow portion would be higher than the water can ever get. I should have it all together by September. At least the plumping part. Once set up it will be slick as a whistle.