Was reading another thread on size of filter and someone said you need a filter 3 times the size of your tank for Cichlids. My tank says it's 290L and I bought the Eheim Pro II thermofilter 2126 which is for tanks up to 350L it says filter volume 4,91/1,08 Imp Gals and pump output 950L per hr 209 Imp gals per hour. Have a made a boob and bought too small a filter?