GPH for sharks

[psusocr]

since im going to have sharks,rays,eels etc. how many gph wet/dry system should i get...I need to know for a 180 gallon tank and for my 269??

 

[gasguzzler]

The same basic rules still apply. 7-10x the volume of water an hour turnover. I always add at least an additional 1000 gallons in powerheads just for good measure. In my 125, I had 2 Mag Drive 750's, 2 Fluval 404's, custom skimmer, UV and the 1000 gallon powerheads I mentioned.
Flow at least 1000 gallons out of the wet/dry in the 180 not including the extra powerheads.