It's not in the ideal range, no. They usually like a lower pH in the 5-6.8 range.
With that said, some people have lucky raising them in a higher pH. As Soothing said, if they are doing ok, don't mess with it. The best way to lower pH is active substrate + RO water and that means tearing your tank apart, buying jugs of RO or getting an RO machine, etc. Also, what is your end goal, just to have nice CRS in a tank and if you get some babies and they are self sustaining, fine or breeding and getting the max out of them you can.
Since there are lots of hiding spots, I assume it's planted well and it's a nice planted tank with some shrimp?