Brain is croaking.....

[Ruth]

Just to add to Bev's list what brand of test kits are you using? Maybe try and take a sample into a LFS and have them test and see if the #'s are the same. I know that I was shocked at what I got for a reading on PO4 from my Salifert kit (supposed to be one of the better brands) and a Hanna colorimeter test. My PO4 was significantly higher than I thought and it certainly told me why I was having a problem with my SPS browning out on me and in some cases dieing.