herbie overflow and sump water level

[skraj011]

I run a herbie style overflow to a sump. I have a feeling that I am seeing some fluctuation in the water level of the return portion of the sump. I want to set up my auto-top off in that section, but I'm a little bit nervous given the fluctuating water level.

Opinions/comments?

[das75]

when I ran a herbie on a 33g QT found the sump level constant. How much variation you seeing? If it's something like a 1/4" probably wouldn't worry as you'll find a ATO float will have a range anyway but eventually all will stabilize at the upper limit.

wondering if you'll get a better response to this in the Herbie thread (http://reefcentral.com/forums/showthread.php?t=344892)

[Indymann99]

my Herbie is 100% stable in the sump water level. after return pump shutdown (waterchange) it DOES take about 15 min for the return section to normalize but after that all is good. I uses a JBJ ATO and works great with float in return section.

http://i300.photobucket.com/albums/nn10/Indymann99/Sump12132009.jpg

http://i300.photobucket.com/albums/nn10/Indymann99/PumpONOFF.jpg