If your ca
is 500, a balanced alk
reading is about 19.5 dKH
. Your chemistry is out of whack.
The LFS says they have to buffer Tropic Marin Pro quite a bit to get its pH up to 8.3.
What do they buffer with? Adding buffer also increases alk
. You don't need to raise your alk
, you need to let your ca
drop. With your alk
at 8 dKH
, a balanced ca
level is around 410.
Is there really proof that pH below 8 prevents calcification in SPS?
Here's a pretty in depth chemistry article
by Randy Holmes-Farley.
And a little quote from the article..."It is well known in the scientific literature, if not in the reefkeeping hobby, that calcification is slowed considerably as the pH is lowered below natural levels. This result is especially concerning and is a hot topic of research because of the decrease in the pH of the oceans as CO2
is added to the atmosphere. The predictions of reduced calcification in coral reefs in the future are substantial."
It also says..."As the pH of the external fluid is lowered, it becomes harder and harder for cells to excrete the excess protons that come about from calcification. That is, they take in bicarbonate, strip off a proton, precipitate the carbonate into their skeleton and then have to do something with that proton. Many of those protons can be used to make CO2
out of bicarbonate, and may thereby boost the rate of photosynthesis. Still, not all of the protons may be used this way, and some will be excreted."