Just set up a new 75 gallon tank yesterday. Just have the canister filter running, the heater of course, no fish yet. The temp is where it should be and while the water was very acidic at first, the PH seems to be coming up a bit. The water seems yellow though but I can't tell if ti's just because of the gravel (natural) or the drift wood etc... I don't have any plants in it yet. Will this eventually go away? Never ran a tank this big before.