I don’t think you want to dose Probio now, as this will reduce your nutrients even more. YelloSno is fine to dose, but start low, 1/4 recommended dose. With anything new, ease into it slowly. Tell us more about your tank, fish, feedings, etcI just got an order of the PNS Pro Bio and Yellosno and Ocean Magik, do you dose the whole bottle at once? Newer system, about 4 months and fighting a little dino due to low nutrient - Nitrate are around 3 and PO is .02. Thanks.