"Eric Schreiber" eric at ericschreiber dot com wrote in message
...

I would start with reducing or eliminating the phosphorous, and see
what happens. Unfortunately, there is no fast, sure-fire way to figure
it out, you'll just have to experiment with small changes and see what
effect they have. The fact that you do such a large water change each
week should help speed the experiment.

OK, thanks Eric. You are a highly respected contributor to this group so I
will cut the Phosphorous back to 3ml for a month or so and watch what
happens. Much obliged.