delteck 501 help

[boots]

hellow every one

I seem to be having troble with my ca reactor,deltek 501.
I set up the reactor 2 weeks ago.
I am now at a bubble count of 1 every 3 sec. with a ph reading of 6.90 to 7.00
the out flow is turnd down as far as i can get it with out the fitting for the ph probe leaking.but I am still having trouble getting the ph down to around 6.5.
any suggestions would be great


thanks boots