Before I can answer that. Let me know this. You said you have a bio cube. With that said, there should be a built in sump compartment in the rear of the tank correct? If that's the case then you would want to put the skimmer in the back where the sump is. The maxijet 900 is too weak to do anything IMO. Id upgrade to a 1200, and if room permits it then do a mag 2 or 3. That will allow it to produce more bubbles due to the higher flow rate
Thanks,
Hoang Nguyen
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