# PVC overflow



## Jakemonaghan90 (Nov 30, 2008)

I want to buildca PVC overflow, and I've seen plans but they still don't make much sense to me.

Can anybody explain the principle of them to me?

It will make the design process a lot easier...


----------



## afoctober2 (Apr 7, 2007)

I don't know if you saw this site the idea is to prevent the tank from emptying if pump were to fail or power went out.

http://www.aquariumlife.net/projects/di ... ow/120.asp


----------



## KaiserSousay (Nov 2, 2008)

Check the first pic in my "sump is done" post. It shows the completed PVC overflow.








That is what it looked like prior to finish. The only *critical* piece is the T fitting, that is the level at which your siphion will stop, so as not to overflow your sump should the pump stop.
Help ya any? :-?


----------



## Jakemonaghan90 (Nov 30, 2008)

Yes, that's awesome. Thanks a lot.


----------



## willny1 (Nov 17, 2008)

Jakemonaghan90 said:


> I want to buildca PVC overflow, and I've seen plans but they still don't make much sense to me.
> 
> Can anybody explain the principle of them to me?
> 
> It will make the design process a lot easier...


It is a lot easier to build them then to understand them :lol: Been there myself.

Just uses the basic principle of gravity. It creates suction, then pushes it.


----------



## khaki (Jan 12, 2008)

i dont get it. What happen if your pump stopped running? Water is still going to go down your sump...right? I would hate to clean up that mess if it overflow.


----------



## KaiserSousay (Nov 2, 2008)

Hey khaki..look at the pic. above..see the T shaped fitting.. if your pump should stop, water will continue to go into your sump untill the water level reaches that T..
Think of 2 buckets, you are siphioning from one to the other, raise the one you are putting water in level with the one you are taking water out of..the flow will stop when they are at the same level...the pipe going into your tank is one bucket, the T is the other..as long as your pump is working the T level will always be lower..when pump stops your tank level drops, when it is even with the T it is like having the 2 buckets level, the flow will stop.
Whew..to much thinking, makes my head hurt  
Hope this helps ya get a handle on how this works :thumb: 
BTW...once your pump starts, bucket gets lowered, your siphion will start again, all by it`s self.


----------



## Jakemonaghan90 (Nov 30, 2008)

A thing of beauty...


----------



## Deeda (Oct 12, 2012)

Here is a link to an animation of how the DIY PVC overflow works properly. I will be building three of them this weekend.

http://www.monsterfishkeepers.com/forum ... 1212442366


----------



## Jakemonaghan90 (Nov 30, 2008)

I finished my first pvc overflow today, and i am pretty happy with it. I capped the intake pipe, and drilled holes up the tube.

I gave it test run today by siphoning water into a 5 gallon bucket until the siphon broke. No problems there.

The only problem is that it seems to be really slow. It only moves a small amount of water. At this point, it kind of just pees into the bucket.

Anybody experience this problem and/or know why it is happening and how to fix it?

Thanks much.


----------



## afoctober2 (Apr 7, 2007)

What size pvc did you use?


----------



## Jakemonaghan90 (Nov 30, 2008)

3/4 inch PVC. The only thing I can think of is that I did t drill enough holes for the intake tube.

I feel confident that I drilled enough though...


----------



## mithesaint (Oct 31, 2006)

Assuming you used Kaiser's design....That is a siphon driven over flow. The strength of the siphon depends on the distance between the water level and the T fitting where water leaves the over flow to go to the sump. When they're close like that, you can't get much siphon. It works, but not as well as it could.

Look at the MFK design. That's a better design. That's how i built mine, and they work well.


----------



## NiteJammin (Jun 28, 2004)

mithesaint,

What is the MFK design? I am looking at building a pvc overflow but I only know of the design posted above.


----------



## Deeda (Oct 12, 2012)

Look at the link I posted above. MFK=Monster Fish Keepers


----------



## willny1 (Nov 17, 2008)

NiteJammin said:


> mithesaint,
> 
> What is the MFK design? I am looking at building a pvc overflow but I only know of the design posted above.


69 page thread about a pvc overflow. All you will need to know.

http://www.monsterfishkeepers.com/forums/showthread.php?t=15733


----------



## NiteJammin (Jun 28, 2004)

Any links to build designs and pros and cons of the two systems?


----------



## Jakemonaghan90 (Nov 30, 2008)

This is so irritating.

I finished my PVC overflow. Not the MFK design. The other one...

Anyway, I originally was having problems getting the overflow to fully siphon. Since then, i have corrected that issue, and gotten all air out of the overflow, so that works fine. However, i tested to see if it would regain its siphon all by itself, and it didnt. So its pretty worthless at this point.

I cant see what i did wrong. Its basically the exact same design as Kaisers.

Any ideas?


----------



## afoctober2 (Apr 7, 2007)

I'm going to try the MFK design hopefully you didn't permanently glue the pvc togehter


----------



## KaiserSousay (Nov 2, 2008)

If the siphion will not restart, you must be pulling air from somewhere. Mine has stopped and restarted many times. I even took off for the weekend, must admit I was a little worried. :roll: 
Not sure whay you are having trouble??? :-? 
Any way to get some pics?


----------



## Jakemonaghan90 (Nov 30, 2008)

I tried the MFK design. Strike friggin Two. This one wont regain its siphon either.

I would put a picture in, but i cant figure out how. [/img]


----------



## auratum (Jul 6, 2006)

I have 5 of the MFK designs operating and they have all worked very well for me.

You need to make sure you don't have air leaks in the pipe as this will break the siphon. You need to make sure you have a high point vent with a air line check valve so you can keep (suck) the air out of the loop that goes over the tank wall. You want to make sure your screen does not have too much pressure drop - the are of the holes you drilled needs to add up to more than the cross sectional area of the pipe you are using (muliply the area of each hole x the number of holes) For area - it is 3.14159 x radius of the hole x radius of the hole (PI*R^2).

This is a gravity system therefore seemingly small amounts of pressure drop can really affect the operation of the syphon overflow.

At some point I will post a write up of the DIY filter for my 150. It has 4 overflows working together to handle the volume of my pump.

Stick with it and you will figure it out.

Patrick


----------



## mithesaint (Oct 31, 2006)

Jakemonaghan90 said:


> I tried the MFK design. Strike friggin Two. This one wont regain its siphon either.
> 
> I would put a picture in, but i cant figure out how. [/img]


Maybe try asking a mod for help putting a picture in? Where are your pictures hosted at? I usually use photobucket. They have a little tag to click on that helps with inserting the pictures. Pics would make all the difference in the world right now.


----------



## Jakemonaghan90 (Nov 30, 2008)

Success! I got the MFK design to work. Im pretty happy about that...

I have my sump made out of a ten gallon tank completed as well. Now its time to search for a pump. After I have the pump, I will be attempting a diy FBF. I think rather than fabricating acrylic or using pvc, ill pick up a properly shaped vase and go from there...

Thanks for all the help everyone.


----------



## mcorbeil (Jan 16, 2007)

Here's a link to my design,

http://canadafishtank.com/wp_marcel/200 ... -overflow/

May not be as pretty , but it doesn't get more simple and inexpensive than this. Good luck! :thumb:


----------



## KaiserSousay (Nov 2, 2008)

Good for you jake..glad you got it :thumb: 
Hey mcorbeil..looked at your design..you are my kind of people


----------



## boredatwork (Sep 14, 2007)

You can actually combine the two designs.

One thing I experimented with was using the mcorbeil design on the inside of the tank and the PVC pretzel on the outside of the tank. This way you get a surface skimmer with a clean look on the inside of the tank, and you can achieve a smaller clearance behind the tank than you would need with the (hot orange) pitcher or plastic overflow box.


----------

