If anything I think the low nitrate persisted for a while. I have been feeding more frequently but it doesn’t seem to be enough. My phosphate didn’t drop out when I started dosing but I have been keeping track of it.This is key IMHO - nicely written. I'm not sure its nitrate and PO4 if it was low for just a short time - but if there was a quick drop - or it persisted for a while, this could be the issue.