hang on tank overflow box question

[chefssaltyballs]

can someone tell me what makes an overflow box noisy or quiet? what determines how much gurgle you will get as the water is sucked from the overflow down to to the sump? I was reading the extemely overpriced lifereef page and it stated that

"Optional AquaSilencer can be used on prefilters that don't run quiet."
if i am buying there system why do they not know if its going to gurgle out of the box?
is it the strength of the return pumps in the sump?? does it mean its to strong if it gurgles... ?
I am planning to make my own overflow box using the exact dimensions of the life reef box (maybe a little bigger as i have a 150 gallon tank and there box is rated slightly less.) i am running two rio hf20 return pumps 2 - 1" bulks from the overflow to the sump... 3/4" returns to two scwds dropping 4 return lines into the tank what must be done to determine or rather avoid the gurgles ??? i have seen tanks with and without the overflow noise that did not have silencers... whats the trick???
thanks in advance for the help
CFSB

[ihopss]

If there is a air pocket in the U tube it will gurgle,are you using the sponge filter,if so that will make it noisy to.

[USC-fan]

two main things make the overflow noisy: air escaping the return tube and the water falling.

To make mine quiet. I have my return tube in an half arch so the water doesn't fall fast. You could use a valve also to slow the water down.

The second thing I did was to put a small air line in the return tube to let the air escape.

[chefssaltyballs]

USC- fan is that return tube like an upside down J? does the end of the J sit the same place in the water that the intital tube would have sat before the J was installed?

the falling water is the noise i am refering to.. its the swirling down the 1" bulks kinda like when a sink full of water is almost empty how it creates a whirlpool in the center with an airhole in the center of the swirl... that hole is where the gurgle is created.

[IPT]

try tanking some airline or small diameter rigid tube and slowly dropping it into the whirlpool (down the drain pipe). There is likely a sweet spot where it will mix the air and water nicely and significantly if not completly eliminate the noise.

[sjm817]

<a href=showthread.php?s=&postid=11916567#post11916567 target=_blank>Originally posted</a> by chefssaltyballs
why do they not know if its going to gurgle out of the box?
is it the strength of the return pumps in the sump?? does it mean its to strong if it gurgles... ?

Yes, it depends on how much flow you push through it, the type of drain plumbing setup, etc. No two setups are the same. generally, the higher the flow, the more noise you will have to deal with.

[chefssaltyballs]

sjm817, thank u. Can u or anyone at life reef tell me how many GPh is the max for the largest lifereef overflow box can run before it starts to gurgle

[chefssaltyballs]

IPT I will try this first.
what size tubing? And where do u fasten it to keep it from gettng sucked in the tube