pvc overflow questions

[TKByrnes]

Ok here is what i would like to do and would like all of your input on if you think it would work or not. i was thinking about building an overflow with pvc pipe and having it come over the back of my tank and into the water then making 2 90 deg bends and then just to the top of the water so it pulls the water off the top. in the pipe that goes over the back of my tank have a little airline hookup and hook it to a powerhead in my tank so if it breaks the siphen the powerhead will pull the air out and start it again.

Now what im not sure about is how many gph pump to what size pipe. I would like to run about 500-800 gph but im not sure about pipe size to keep it flowing at the right rate so it A: doesnt overflow the tank. and B: doesnt overflow the sump.

If i need to I can put in 2 overflows because i know it is always good to have a backup.

If any of you have done this or know the pipe size i should use i would greatly apreciate it. Pics would also be great if anyone is running a setup like this.

I was looking into having my tank drilled but it is already established and really dont want to take it all apart to have it drilled. also I really dont want a hang on overflow on the back of my tank. please help! Thank you all in advance.

 

[outy]

syphon overflows are out and work, your idea though on paper is not the worst but has a great chance of failure with a tank overflowing water everywhere.

heres the best

#1 drill the tank with 60% water left in [read up its been done.
#2 deal with a hob u tube
#3get a cpr syphon type overflow. [hated by many but i have mine set up and overflow proof]

 

[Laakmann]

I have a built working pvc pipe siphon overflows before, basicly here is the stats I have

the biggest size I found that I could use is 1in diameter pipe. Building one overflow will get you at most 600 gph but depeding on how much pull there is on your siphon it could be less.

I wish I had pics of it though.


This is the only pic I could find on the web and this is mmmmuch more complicated than my design but most likly gets more gph.

http://www.nd.edu/~lego/grp2/www/reef/diy/overflow_1024.jpg


mine is basicly a shorter U that goes in the tank with the intake on one end and the siphon on the other which siphons into a longer U on the outside of the tank where the water is allowed to pool and overflow into a T connector that is on the none siphon part of the U and it is lower than the water level in the tank but higher than the bottom of the siphon.




I started the siphon by closing off the outtake and inhaling into the none siphon part of the outside U which is an open pipe that is higher than the water level in the tank.



I am sorry I dont have pics, it would be much easier to explain with them

The

 

[MinibowMatt]

i tried this and it worked ok. its tuff to make sure the siphon re-starts.. here are some pics:

 

[TKByrnes]

minibowmatt what size pipe is that? the siphon and return