"LeighMo" wrote in message
...

snip

Yup. And even worse things can happen. With high light and no CO2
injection,
the pH can shoot up so much and so fast it hurts, even kills, the fish.

I experienced this with only 2wpg. I checked the pH two days after putting
in many plants and installing the light, and it was 9. That's why I got
into CO2 so quickly.

bob