A little impatient today, eh?
Lowering gravity and raising pH at the same time is a tough one. Are you measuring your gravity with a refractometer? If using a swing arm hydrometer, then you should probably invest in a refractometer to make sure what your gravity truly is.
But assuming your SG
is really 1.028, I would probably just do some water changes with lower than normal specific gravity water. You can calculate out the expected "after" SG
based on your PWC
water and the volume you change. For example, say you're changing out 20% using 1.022 then your final SG
(0.80 * 1.028 ) + (0.20 * 1.022 ) = 1.0268
... where the "0.20" is the percent you're changing and the "1.022" is the PWC
water salinity. I wouldn't drop more than 0.001 in specific gravity per change... preferable half of that.
If you're trying to keep your pH from dropping any more, then doing PWC
with more dilute salt water than your target is probably best. That way you get some buffers in the water. Once you get to your target salinity, then you can see where you're at with the pH and go from there.