How big is your tank and how many ml of pellets are you running? They take a while to fully kick in, so I wouldn't call one month fully kicked in. Every horror story you hear about biopellets is because people run too many. I consider the directions on the package WAY too many. I recommend using pellets to assist you in keeping nutrients low, but don't treat them like a silver nitrate bullet.
I run about 300 ml on about 250 gallons and my nitrates climb up from time to time, but usually hover just above zero. You won't ever lock it in at a precise number because things always change.....feed heavier for a few days, don't change that filter sock for a few extra days, detritus build up in your tank, etc.
Ive been running pellets for over two years and wouldn't go without. They work well but are easy to screw up too. I recommend waiting a few more weeks before making a change.
