help filter and nitrite question????

[newsalter]

I need to know if my bio wheels im running need to have just a regular pre filter pad in them or a carbon pad in it? my nitrites were at 0 now they have spiked up to 1 again. my tank has been up for 5 weeks now.
everything else is still on the mark.
also i have put 2 packs of bio spiria in it over the last 2 weeks. my son has his puffer in this tank and he is seeming sluggish. the tank is a 46 bow front.
i have another tank that is set up and running fine i could transfer him to it.
my other tank has 2 clowns and 2 triggers???
help??????????

 

[ci11337]

i would take out the wheels, as long as you have LR. All you need is that pad that has carbon in it. that removes detritus and then the carbon removes odors/colors etc.