from what I have read , 7.9 is ok, 8.2 is ok. Little PH swings can be normal and don't necessarily mandate dosing. A good water change will probably do the trick.
Finger Leathers require medium to high lighting combined with medium to strong water movement. I'd keep it near the top of your tank. (been reading alot about this) For continued good health, you probably want to do a tiny dose of iodine, strontium, and other trace elements to the water (depending on your mix and what comes in it)
Leathers are really cool. I'm dying to add one myself. they are peaceful but do require some space - I'd say a few inches in each direction
I've heard mixed reviews about carbon - it pulls nitrates and other stuff out of the water, true, but many folks dont use it and I have read plenty of threads where peoples corals have had bad reactions to carbon if left in too long so they will put the pack in for a day then take it out. Probably best to get another opinion or two on this one - maybe start a new thread.
