175g Saltwater predator tank - Update:Aug 10th/10- FISH ADDED

[snow1]

Hey all so far it's going good, new pics or video will be up tomorrow. I went into work today and tested my water. I was actually very surprised by the results. Nothing bad is showing up and infact the tank seems ready for fish but I can't get any until I get back. Just have some problems though that maybe you all can help with:

The temp of the tank is 73F. This is to low correct? It should be around 78F? I need to go and buy another heater b/c the one I have is not strong enough I guess.
The PH is at 7.5, is this to low for marine fish? I hear mixed opinions? Some say it should be around 8.

Any input? Thanks.