i have all the above mentioned filters except the fosters brand,..
i personally wouldn't go with the emperor, it a pain in the you know,.. losses its prime when power goes off and needs re primed pain if your not home,.. and water level is low due to evaporation
penguins great,.. no complaints
aqua clears are great if you use them modded like cogunner has them,.. if not they are a pain to keep clean if you don't they pop up out of canister,..
fosters looks good but no experience,...
sun sun i have and never looked at lt since great little filter for the money,..
hot mag is great also but when really dirty flow slows down, but only after a while... i have 3
depending on your stocking level and time you spend to cleaning filters
all will be great,..
if you want a set it and forget it filter
as i forget to do maintenance when i need to,..
I'd go with a sun sun, or penguin double or hot mag,.. or modded ac
if using regular hob penguin or emperor, or fosters get double volume tank size if you can,..
and use the imagine inserts they save you money,.. i use the clam shell with just walmart quilting batting,.. very easy to cut to fit the clamshell,..
http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=11352&rel=1
as said before i own all but the fosters filter and speaking from what i have delt with,.. not what i've heard,..
and i want to forget the filters,.. and emperor filters clog and flow slows and i have a penguin 350 on my 90 goldfish tank along with an ac1000 and a sunsun and ac is always full but since modding it the flow still goes on,.. and the penguin is still running great even though it catches tons of litteral crap,.. and the sun sun is still runn good,.. so all i can say is my filters take a beating,.. and the issues are only with what was stated,..
i hate to mess with filters,.. i do it when i want to,....... not when running out the door and i hear a filter whinning to be cleaned wa wa wa,..
just saying,..
