My DIY pvc overflow, will it work?

[MBilyeu]

None of the pieces are cut yet, but hopefully you can get the idea from the pictures. I was wondering if that design will work? Also to prime the overflow, I was going to install the ball valve and close it. Then fill the overflow via the upturned pipe in pic 2. Then when it is full, open the ball valve. That should create the suction needed to prime the pipes, correct?

Another question: In the articles that I have been reading, they say to position the t-pipe so that the middle of the T is where you want the lowest water level to be. Well wouldn't you want to position it so that the water level will be even with the top of the T? As soon as the water level drops below the top of the pipe, air will then be entering the system, and stop the suction correct?

 

[Pharaoh]

Where are you planning on putting the "T"?

You should install an air check valve at the top of the "U" bend in order to remove the air and create a siphon. Air will eventually build up in there and stop the siphon.

 

[MBilyeu]

The T will be inserted into the pipe that it is next to, but will be much closer to the top of the tank. These pipes will be cut shorter when I am ready to glue them, I just wanted to post pics to make sure that my thoughts were correct. The pipe on the left is the intake pipe which will have a plug in the end and quite a few holes drilled into it. It then bends over the edge of the tank and down to where the two elbows aren't connected yet. Then will come back up the right hand pipe where the T will be inserted near the top (which I am uncertain where exactly). Then the part of the T that in facing the ball check valve will go to the sump while the other continues up to the two elbows which will not be glued together, so that I can turn them any way needed. The reason that I am concerned about where exactly to put the T, is that for each 1" it is lower than the water level, it will drain 12 gallons into the sump which will be a 55 gallon tank. I wanted to fill the sump halfway, and put the siphon break point 2" below the water line before I started the siphon. Which in the event of a power failure would still keep the sump about 5 gallons from overflowing. Does this mean that the very top of the part of the T facing the valve in the picture should be at the 2" mark? Or the middle of the pipe? This is what I am confused on. Even after all of that I am still not sure I explained it well enough.

I don't know where to find the air check valve. Would it be somewhere in Home Depot, or will I need to get that from an LFS? That is the thing that you drill into the first bend at the top correct?

 

[Pharaoh]

Any way you could draw something up in MSPaint? Sorry, I'm a visual person.

 

[MBilyeu]

Ok, here is my horrible paint skills. I tried to draw it up just like the layout in the photograph, so the photo will make more sense. My thoughts were that I should put the T to where the lowest water level I want would be on line #1. Both articles I read said that the lowest water line should be in the middle of the T which is represented by #2. It is important to be correct because it could result in almost a 10 gallon swing either way.

Next question, does the magenta arrow represent where the air check valve goes? Where do I obtain one? Is it possibly called something else in some wierd section?

Thank you for helping me.

 

[MBilyeu]

Bump

 

[greenterra]

Yes it will work. I modified your pic a little to help. Like any overflow, setting the hieght for the water level is the hardest part.The best thing about this style overflow is its ability to source water from the bottom of your tank.



I run the same setup on my tank with a home made filter I have made from an extra large poly esky. Instead of using a check valve in the u section over the tank wall, I just have a small pipe glued in here with air line tubing going from here to the venturi on a powerhead. It automatically sucks the air out of the overflow and starts the syphon.

 

[MBilyeu]

Ok, so I just insert a little tube in there and connect something like this:

http://www.bigalsonline.com/BigAlsU.../cl0/aquariumsystemsmaxijet400powerhead106gph

Which I will have running in my sump in order to keep the siphon going? If the power ever cuts, then when it comes back on, this powerhead will make sure the whole system starts up again?

Another question: On the vent pipe, if the part that goes back over the tank wall touches the water level, should it be turn sideways to keep it out of the water, or will it matter if it is in the water?

 

[greenterra]

Ok, so I just insert a little tube in there and connect something like this:

http://www.bigalsonline.com/BigAlsU.../cl0/aquariumsystemsmaxijet400powerhead106gph

Which I will have running in my sump in order to keep the siphon going? If the power ever cuts, then when it comes back on, this powerhead will make sure the whole system starts up again?

Another question: On the vent pipe, if the part that goes back over the tank wall touches the water level, should it be turn sideways to keep it out of the water, or will it matter if it is in the water?

If you use a powerhead to draw the air, it will have to be in your tank. If you have it in the sump, it will continually drain into your sump in the event of a power failure. Slowly but surely.

The vent pipe is to allow the system to break the syphon which allows it to drain down to the T section and no further. It needs to be open and above your tank.

 

[MBilyeu]

Check on the vent pipe.


I don't want anything else in the tank, that is one reason I am going the sump route instead of an fx5 or the like. So I am not really sure about the air check valve. It would seem to me that after the first priming, that it is pointless(I have never had a sump/overlfow before). Pharoh mentioned that air will eventually get caught in the overflow, and then the siphon will stop. It seems to me that if that air check tube isn't there, then air wouldn't be able to get in.

I am probably sounding pretty ingnorant (which I am), but I just can't understand the purpose of it. I watch you-tube videos on overflows, and it seems like they just use it to prime the overflow, then they disconnect the air pump and that is that.

I am going to try and find some different articles online, because this is still a little confusing.