"Bob A" wrote in message
...

However, I'm normally KH 4 and pH around 6.6. Past couple of days pH is
up
to a steady 7.1.


How long since you recharged your co2 bottles? They may have stopped
producing, they only live for about 10-14 days. How many bottles are you
using? In a 55, no less than 3 two-litre bottles would be needed. I use 2 on
a 45.

billy