IME it’s normal. Mine were undetectable for a long time until I started dosing NO3 and PO4 to battle dinos. Phosphates can bind up in live rock until the rock basically has no more room, at which point it will release back into the water column and show up on tests.
Try to keep your nutrient level low but not 0 for extended periods of time. 0 nutrients can open the door for dinos to take over and that’s not a problem you want to have - trust me!
Try to keep your nutrient level low but not 0 for extended periods of time. 0 nutrients can open the door for dinos to take over and that’s not a problem you want to have - trust me!