calcium reactor and Ph

[joeycadre]

i've been running a geo 618 on my 90 gallon sps tank for a month now and the ph on my tank is running around 8.0 (day)- 7.83 (night). i have my ac jr set to turn on my CO2 at 6.45 and off at 6.55. i'm using pci large grain media.

so what gives. I know why my ph is so low, but how do you fix it?

my calcium is running at 450 and my alk is 11

[BigBadBlenny]

i just got a Pm cA reactor. i havent set it up yet but here is what they say in the instructions.

to raise ph, increase the water flow or decrease CO2
to lower ph, decrease water flow or increase CO2

also they recommend carib sea A.R.M. media because it dissolves at a higher ph

this isnt my experiance like i said i just got the thing and havent even used it yet. this is just what they have in the set up instructions.

[SDguy]

I just drip limewater as my topoff water. Offsets the lower pH from the reactor.