I'm trying the borax trick again. I always get mustard pretty bad, and with the recent heat wave here, water temps are pushing 90 (!) I bought some test strips, which seem to work ok (drops based borate test is prohibitively expensive!) I need to drop another box in, but from the 1 box I put in, it kinda seems to have slowed stuff a bit. Also, somewhat hard for me to tell, since i've been getting home later in the evening, so there's not enough light to really see. This weekend I will have the other box in there, which should put me right at 45 - 50 ppm borate. I'll give it a good brushing and if it doesn't come back, I'll claim success!

Michael