leave all powerheads on 24/7?

[kien]

I put my two Tunze into sleep mode as well (50% of normal output). I have a couple of fish that hover to sleep and they seem to appreciate it (not as restless at night). I also have tiny shrimp (sexy and glass) that come out at night. No problems with anyone in this mode of operation so far.

[freezetyle]

the only problem i would see if you have them set up on a timer smaller fish may crawl into where the propeller is and when its time for start up get mangled. i would leave them on. unless you have the tunze or vortech which like previously stated just slows down at night

[mike31154]

Since installing a second VorTech in my system I've started using the 'slower' night mode. Been quite a while now and no apparent problems with lack of O2 at night. I wouldn't do it with just one though, don't think it would have been sufficient.