200lt
6x30w fluro lights

That's a lot of light. Well over 3 wpg. You need to make sure you have plenty
of CO2 with this light level.

(the water is really soft here.. carbonate and general hardness both about
40ppm.. i have been buffering it)

What is your pH and KH? That tells you more about how much CO2 you have than
the bubble rate. Try measuring it in the morning, just before the lights go
on, and in the evening, just before they go off.

And what have you been buffering the water with?

Also, you may need to add fertilizers. If not now, eventually, you will. With
this lighting level, you'll need to add plenty.


Leigh

http://www.fortunecity.com/lavender/halloween/881/