Durso question

i am buying a brand new 90 gallon. the durso standpipe that is in it has a drill hole on the side about the same level as where water would flow into the main pipe. i dont really understand y this is there??
and the return line doesnt have a siphon break at all.
all i am used to is external overflow boxes so i dont know to much about internal and drilled.

and body have a idea why there is a hole in the standpipe and not the return pipe?

 

i think its there to allow air in for the water to flow better to the sump. without it you get gurgling or a toilet flushing sound.

 

Yeah, that would be my guess.

Is it an AGA / aqueon durso, (megaflow) or a home made one, or another brand?

You can easily make your own for cheap for the tank.

 

well there is already a hole in the top of the pipe with a small airline through it.
i thought that was what was gunna not get the flushing sound. ive never seen a hole on the side of the pipe. and again this is a brand new marineland tank predrilled with return and standpipe.

 

mine is a 72 gallon. it has 3 holes in the site and 1 in the top. if you cover it you get slurping. when you let go it maintains the water leval and no slurping.

 

What kind of return outlet do you have, and how much sump capacity for back flow?

I sealed my anti siphon hole on my return because the LFS guy drilled it at the exact worst spot he possibly could have to produce a loud splashing noise. I keep my return outlet slightly less than an inch below the water line, so the siphon breaks naturally well before my sump fills.