the
bio wheels tend to create more nitrates than remove them. The bacteria required to remove trates is anerobic bacteria whch means oxygen free. that bacteria can not thrive if is contacting air.
if the ffilter is floss or sponge then you are adding fuel to the fire. in my nano i use a floss filter with carbon and change the pads about every 1-2 weeks or so. carbon is really only beneficial for about 1 month typically. floss and sponge will usually create more nitrates as well. i only use them as a
mechanical filter. LR for bio filter and the carbon for chemical filter. my tank seems to do well like this.
HTH
BR