Seio 620 or 820

[Solitaryensis]

Hey guys,
Im not getting very good circulation in my tank now and was thinking of picking up a seio 620 or 820. The tank currently houses SPS and sofites. I was wondering what you guys would reccomend.

The tanks a 40 gallon and is 3 feet long. I plan on having only one powerhead on the side where i have SPS. Ive never used seios so i need your opinions.

Also, how far are you guys keeping the pumps from corals?

Thanks,
Theo

 

[gfk]

id get 820s, i have 620's in my 29 gallon and i almost wish i had 820s