Thanks everybody esp Frank I. Reiter and Olga Betts for pointing out the NO3 deficiency that *could* lead to my BBA problem (my test kit register 0 ppm NO3). But I am still not able to get my KNO3 yet due to the long Chinese Holiday. In this part of the world, business will kick off again, *normally* on 24th Feb ! To all Chinese list members, Happy Chinese New Year. rgds.