Dear SH, The reason I think it is K is because the other chemicals are all in check like the nitrate 2-5 ppm. So, the K is the one that sticks out the most I use the aquarium landscape kit from Fish-vet.com... The other thing that could of caused it is the nitrate but is was added slowly into the tank unless a 2ppm to a 5ppm increase during 5 days was to much? But, to get is to jump up I guess the K level went to high. Hey while I am writing has anyone taken the Bio-balls out of there water-drys to let the nitrate build that way to?? AZ _______________________________________________ AGA-Member mailing list AGA-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/aga-member