Water parameters

["heather&mike" <haines@perth.igs.net>]

I have been planning to start up my first apistos tank - probably a.
caucatoides, borelli, mcmasteri or agassizi.  I just did a routine water
test in my existing tanks (corys, angels, tetras) and discover that my Ph
level has taken a jump from 7.0 to 7.6.
Kh is 3, Gh is 7.
 Ammonia and nitrites are 0.  Nitrates >20 <30.
I plan to put the fish in a 20 gal. long tank with probably an AquaClear 200
filter.
Should I be concerned about the Ph level?
What might cause it to jump like that?  I haven't been using anything to
alter levels.  The only thing I add to my tanks is dechlorinator.
Do the Gh - Kh levels seem reasonable?
I understand that of my 4 choices for apisto starters the caucatoides is
probably the most tolerant of water conditions - is this correct?
Any/all input welcome.  I am anxious to get my new fish but don't want to do
so if conditions are not favourable.  TIA

Heather