My LFS guy swears by the stuff, but it doesn't work for me. I have tried it in two different tanks. One cycled after 6 weeks with really, really high ammonia in the meantime (I didn't know what I was doing as it was my first tank). The other still had not cycled after 8 weeks so I tore it down and am restarting it without the Safe Start. In the meantime, I started a third tank, no Safe Start, and it cycled in 4 weeks.
As for doing no harm, I don't know about that. This guy claims it does do harm: http://www.firsttankguide.net/bacteria.php
So who knows what the answer is, but as for myself I am not going to use it ever again.
As for doing no harm, I don't know about that. This guy claims it does do harm: http://www.firsttankguide.net/bacteria.php
So who knows what the answer is, but as for myself I am not going to use it ever again.
