Originally Posted by maine_guy5
the LFS said to put some crushed coral in with it and that should hold the ph up higher does this seem right?
Your LFS has fallen into a commonly myth that Aragonite stabilized PH. It doesn't. It will just start to slowly dissolve at PH below 7.7 if Alkalinity and Calcium are also low but most saltwater tanks never enounter levels that low.
Low PH is usually excess CO2. Take a good look at your system and see where CO2 can be better removed. Skimmer, waterflow, overstocking, etc. It common for the indoor air to have excess CO2 in the winter when people close up their houses.
That said, I'd agree with the Sushi Hater that it's not really low enough to be concerned about.