Uneven overflow rates in All-in-one tank?

[jason the filter freak]

I have an IM AIO tank that has a much higher flow/return rate on one side vs the other.

 

I swear it's a 28 gal but I can't seem to find any literature on the tank. I'm wondering if it's by design or something else...?

 

I'm using a Sicce 350 ish gal per hour return pump.

The tank appears to be level side to side.

The intake combs/slots are clear.

 

Any suggestions on how to fix it would be great. The flow is too slow for my fuge side and it's killing my cheato

[Origami]

Some detailed pics might help, Jason. 

 

Are the comb slots at exactly the same level? Are the number of slots on each side the same? Does the water rise to the same level on the tank side of each of these slots? Is the water level behind the slots below the bottom of all the slots so that the slots are completely open to flow?

[Origami]

Is it this 30 gallon one? http://www.finsaquaticsusa.com/Innovative-Marine-30-Gallon-NUVO-Fusion-30L-Aquarium-Tank-Only_p_1941.html

 

There's an owners manual that you can download on the page.