Ideal Overflow Water Level

[sg88]

Please help with overflow water level...

Starting to plumb my new 50 gallon cube (my first sump system tank). The emergency drain height (Herbie-style overflow), as it came pre-cut with my SCA aquarium system would put the overflow water level at 4” below the bottom of the weir slits. Is this appropriate? Since I plan to run the Herbie emergency with just a trickle down the tube, Is it better to cut a new, longer emergency drain to allow the water level to be much closer to the weir? Is there an ideal relationship between the bottom of the weir teeth, the overflow water level and the emergency drain level (which I understand to basically be the same as overflow water level in a Herbie-style system.

Appreciate any input.

 

[JohnGP]

I just recently set up my new tank with a Bean Animal style overflow and initially had it set at about that height but found it too noisy so had to cut new longer pipes and adjust from there. You could try it as is but I think you'll find the water flowing through the weir and dropping 4" is a bit loud, mine now only has about a .75-1" drop.

 

[ca1ore]

It's a trade off between noise and capacity. If you get the rim of the secondary/emergency too close to the bottom of the teeth, then in the event of an emergency there may not be enough head pressure building up over the rim to handle all the flow. If you have the space, upsizing the PVC as it comes out of the bulkhead can help a lot.

 

[Chrille26]

Since I have my tank in my livingroom, witch I share with someone who isnt as into this hobby as me, I chose it get it as quiet as possible. For me that means I keep the water level as close to the waterlevel in the dt as possible to avoid the waterfall sounds.

 

[Snoopy 67]

You can always raise it with a coupling or 2, not glued, until satisfied.