Alkalinity High?

shornik · Jul 23, 2014

So here's the question. My tank is about 3.5 months old. I've been dosing just calcium for maybe 1 - 1.5 months now to raise it for the corals I began introducing and in anticipation of adding more - its also helped with my inverts - crazy growth on my fighting conch. Anyway, calcium (Red Sea) has been steadily climbing (about 15 ppm per week for the last several weeks) it is now at 420 ppm. All the usual suspects are good, Ammonia is 0, Nitrite is 0 (at least I think its a color not on API card - light blue) and Nitrates are 5-10 ppm (again hard to differentiate with API card). My magnesium (Red Sea) is usually around 1400 (on average) and my PH is 8.0 and Phosphate as been 0 for the last several weeks (Hannah)

So this all seems relatively fine but my Alkalinity (Red Sea) is way over the place. When I started dosing the calcium it was around 11.9 than it started coming down as my calcium started going up which is what I understood to be what would happen, it got down to 8.85 on July 3. But ever since then even while by calcium has increased from 395 to 420 the alkalinity has climbed back up to 11.5. Any idea why this might be? Everything I've read would lead me to think that the problem I would run into is too low of Alk and less buffering of the PH. I'm not complaining if that is not an issue I have to worry about (there are enough other's in this hobby). I've got mostly softies and LPS in the tank now but I am trying to get parameters in line to start adding SPS and somewhere I read SPS like Alk in the range of 7-8 (or was it 8-9), so I'm concerned - should I be?

ritter6788 · Jul 23, 2014

What salt mix are you using and what is the alkalinity of your newly mixed salt water?

shornik · Jul 23, 2014

Sorry forgot to add that, I get my salt water from my local lfs. I'm about to go there for some top-off water and so I'll ask them what brand/alk level. I've also been doing 5 gallon water changes weekly for my 60 gal tank. Hmmm, maybe a cause? I'll report back later today.

ritter6788 · Jul 23, 2014

shornik said:
Hmmm, maybe a cause?

It would have to be if you aren't dosing anything to increase the alk. It will never go up on it's own. A salt mix like Red Sea Coral Pro has a very high alk.

shornik · Jul 23, 2014

OK, I've returned from the lfs - and my wife wouldn't let me buy any new coral :squigglemouth:

I asked what brand of salt they use and because my memory is so bad I've already forgotten but I looked at the bag and the Alk should be 7.85. So something is odd - they suggested that the live rock that I have which came from them may be causing the high Alk - other than that I have no idea.

Everything in the tank is doing well, fish are fine, corals seem to be fine so maybe I should not obsess about this water param?

BTW, thanks for your reply and thoughts on the issue.

Reefing Madness · Jul 23, 2014

Being as the numbers are all still in line, id not worry to much about it, as your tank will now take over and should lower that alk number on its own.