Funky pH-Ca-Alk: Fixes?

[happyclam]

pH: ~7.8 (API)
Ca: ~400-420 (API)
Alk: ~15 dKH (API)

These are readings from my 130g system. It is located in my basement which has a gas-burning water heater and furnace, so I figure excess CO2 is the cause for the low pH despite very high alk. Everything in the tank seems ok, coraline is looking a little pale and corals have faded a bit, but I assume that is because of my very low light levels (only 4x 96w PC's over the tank). Currently in tank:
1x Yellow tank
2x Diamond goby
2x Blue chromis
1x Sarcophyton
1x Lobophytum
1x Clavularia or Anthelia, not sure
1x Discosoma
2x Peppermint shrimp
plus various snails & hermits

The tank has been running for about 8 months, corals have been in for 1-4 weeks depending on which piece. All fish have been in for at least 2 months.

Should I try correcting my parameters some how, or just leave it?

Thanks for the help!

[Laddy]

How do you control alk and ca? Two part? Ca reactor? Kalk?

You're Alk is way high, and you're pH is not low contrary to what many people believe.

If you allow for proper O2/Co2 exchange in the tank (good surface flow, and control of nutrients) your pH "is what it is", which is a phrase I hate, but it really does apply here.

[happyclam]

parameter maintenance is a weekly 10% w/c with IO salt.

a while ago I added Kent Superbuffer at the recommendation of my LFS to help raise pH, thus the high alk.

[HanoverFist]

This is the best article i've read to date on water parameters and maintaining equilibrium. Does a good job of explaining how to correct each type issue. i.e. high cal, high alk, low alk/high cal, low ph, etc.

Chemistry and the Aquarium by Randy Holmes-Farley (http://www.advancedaquarist.com/issues/nov2002/chem.htm)

[jdieck]

All PH buffers out there are nothing else but alkalinity supplements. Stop dosing alkalinity and just keep adding calcium and magnesium as required until the alkalinity goes back to the proper range.
For your low PH it is more likely high CO2 in the inside air of the house which gets worst in winter when we keep the house closed most of the time. If this is the cause, more surface exchange will not help but you have several options:
1) If you have an skimmer and if you can, try using a hose to feed outside air to the air intake of the skimmer.
2) Switch your supplementation to an alkalinity supplement that tends to maintain a higher PH. If you are not doing so, use limewater (Kalk) to replace your evaporation and maintain your calcium and alkalinity levels.
3) If you have a refugium, add macroalgae and light it on an oposing photoperiod than the main tank, in other words while the main tank is on refugium is off and when the tank is off turn the refugium on. This will reduce the PH cycle over the 24 hour period.
4)Reduce feedings if you feel you are feeding too much specially if you feed plankton for filter feeders. The extra nitrification also tends to lower PH.
5) If you are using a calcium reactor, set it up for low effluent flow at lower PH rather than higher effluent flow at higher PH to supply the same amount of calcium and alkalinity. Drip the effluent at the intake of the skimmer pump.