Suggestions to get tank levels in line?

[meverha1]

Biocube 29. Eventually going to be a mixed reef.

Ammonia 0
Nitrite low
Nitrate medium high (working on it via dosing Vodka)

PH is low (7.9ish according to Apex Probe)
Calcium is sitting around 460 ppm according to Red Sea
Alk is also on the high end
Mg is sitting at around 1200 PPM (Red Sea, again).

Dosing Marine Buffer to raise PH but it doesn't seem to be doing much good.

Started Dosing Red Sea Reef Foundation A & C (Calcium and Mg). Calcium improved immediately but MG is still low. Hovers around 1200 ppm daily, despite dosing with Reef Foundation C.

So, What can I do to raise PH and get my Mg in line without hurting the few fish and frags currently in the tank?

[bertoni]

pH at 7.9 is fairly common for a house with the windows shut. It should be fine; lots of Tanks of the Month run at 7.8. The Marine Buffer is basically just a high pH alkalinity supplement with some borate for part of the alkalinity. The borate will help raise pH, but it can't be used by corals for their skeletons, so it makes measuring carbon alkalinity tricky. The buffer also will drive the alkalinity very high over time. Raising the tank's pH probably will require fresher air, but sometimes Kalk can help a bit.

Raising magnesium requires large doses of supplement. I'd raise the level to 1275 ppm or so, the canonical ocean average, but 1200 ppm is fine. My tanks ran for years at 1100 ppm because Instant Ocean came at that level. This calculator might help picking a dose:

http://reef.diesyst.com/chemcalc/chemcalc.html

The entry for the Tech M probably is reasonably close, but I'd target no more than 25 ppm for the first dose. That's within the error limits of the test kits, but it'll be safe. If the change in the level is small or nonexistent when tested, you can double the dose. Up to 100 ppm per day should be safe.

[meverha1]

Why does pH have anything to do with keeping my windows shut? I'm a bit confused there.

[bertoni]

The pH of our tanks is set primarily by two factors: the amount of carbon dioxide in the air, and the alkalinity level. Carbon dioxide dissolves into carbonic acid in water. Alkalinity acts to neutralize the acid and raise the pH. Closing the windows generally drives the carbon dioxide level up, so the tank pH drops. The effect is worse when there are a lot of people in the house. People report some very low levels when having a party, for example.