Issues with bubble blaster reef octo skimmer

[Just Jim]

I'm having a lot of inconsistencies with my reef octopus 3000 with a bubble blaster 5000. Its an old setup I just started back up and isn't skimming consistent. One minute it's great and then I check on it later and the skim level is way down. I inch it back up and later it's overflowing. Is there anything this could be other than the pump being old? I bought a new Venturi hoping that was it and no luck.

 

[Vinny Kreyling]

If there is no bio load there is nothing to skim on a new tank.
OR there is some but it gets pulled out then stops until there is more.
If you change settings & it starts again it will overflow.