i just bought a used 75 gal setup & it came with a marineland emperor 400b & an aquatech 5-15

will i need to use both filters on the tank??

& also the bio wheels in the emperor filter, do they need to be replaced?? the tank has been sitting at my house for a week empty & i dont know how long the previous owner had it running / empty, so i was just curious if i needed to go ahead & get new bio wheels, they did not send any cartridges so im going to have to get some of those today

thanks & im thinking of setting this tank up w/ lake malawi cichlids

it certainly wouldn't hurt to use both filters.I don't think is that necessary to replace the bio wheels. If they look in reasonably good condition and aunts all chewed up and filthy then they should be okay. Just give them a good clean in very hot water before using them, may be leave them to soak for two or three days.

also if you can repalce the aquatech filter with a aqua clear model(maybe a ac 70).imo the aquatech is much inferior to the aqua clear for both mechanical and biological filtration. dont forget that with the filters dry for a week you will also have to cycle the tank before you introdice fish into it.

marineland recommends that you do not replace the bio wheels unless they become damaged.

thanks for all the info, the bio wheels look practically brand new, no visible damage or algae on them, i think i will soak them in hot water & try & use them

the tank is filled w/ water now & will start cycling in a day or so when i get the bio wheels rinsed off

i did not hook up the aquatech filter yet, i will go look at an aqua clear filter