Tom Barr posted the following on APD:

http://fins.actwin.com/aquatic-plant.../msg00463.html

I was wondering if anyone here knows more about why this is the case, and if there is some way to decide how much based on GH.

I dose my 29 gallon using the generic regime stuck at the top of this forum so I was using 5 ml of plantex CSM+B solution mixed at 1 tbsp. per 250 ml water.

I recently started dosing 10 ml because my water's GH is 22 degrees. Maybe I need more?

Any info would be great. Thanks!

I haven't been doing sufficient water tests over the last 6 or so months to give any real good data, but I'm certainly coming to a similar conclusion. my GH is in the 15+ range. My tank always seemed a bit different, so in the last 2-3 months, I've started upping my trace dosing. Since the dosing was getting quite high, I switched to dry dosing. I'm now up to 3/8 tsp 3x per week, and I've not noticed any problems and the tank seems to be responding better (more growth, more pearling, less BBA). I've actually been wondering how do I know when I've crossed the line and started dosing too much. I've been changing other variables as well, so it's not real controlled. But the increase micros seems to me to be one of the bigger positive contributors.

I'll be interested to hear what others think of this!
Brian.