Educate me on PH

okay, i am almost a year into this and the water chemistry still has me a little confused. i thought that I had my PH around 8.3 (using test kit) but was unsure enough to buy a PH monitor. Now i see that my real PH is around 8.0. I would like to raise my PH but my KH is around 13. How can I raise my PH without raising my KH? I have been using Seachem's reef buffer but it raises the KH along with the PH. Here are my other parameters.

Temp - 79
nitrates - 0
phosphates - 0
calcium - 420
PH - 7.9 (a.m.) 8.0 (p.m.)
Magnesium - ?
KH - 13
salinity - 1.025
Did I forget anything?

Magnesium is the wild card. Everything i test, tank water and freshly mixed, shows 1000. This is even with two different brand salt mixes. So either something is wrong with the test or the tester. I have ordered a new mg test kit and Seachem's reef advantage magnesium. if my magnesium is low, what effect will adding just the magnesium have on the PH or KH if any?

 

I guess i should add that the tank is a 135 gal with a 20 gal fuge and a 15 gal sump. i do have a lid on the dt but i open it at night if that makes a difference. What else do you need to know that might effect the PH?

 

IMO that is a perfectly fine pH... i have seen tanks run as low as 7.7

If you keep it constant there shouldnt be any issues.

pH is a function of many things: oxygen transfer, ORP, rate of photosynthesis, and water movement... to name a few of the major players. The fact that yours is running "low" could be as simple as being in an enclosed room in your house, or as complicated as a slow link in your ORP chain.

 

i don't test for the ORP. i guess that i assumed that with the trickle style sump, skimmer, open-top fuge, and my power heads pointed towards the surface in my dt that i was ok. I also don't THINK that i have too many fish (diamond goby, canary wrasse, dejardini tang, powder blue tang, flame angel, 2 o clowns) However, i do have glass lids on my dt during the day that probably does hurt the oxygen transfer a bit. do you think the lids could make that big of difference?

I guess the reason i think i am low is that everything i read talks about a reef aquarium being at 8.3. Do you not think this makes much of a difference?

 

your tank should be fine with O2 transfer... maybe your room just has lower O2 levels than usual.

The main thing with pH is consistency, not the "correct" number... for instance, this gorgeous tank runs at a constant 7.8-8.0 and the corals literally grow out of the water
http://www.3reef.com/forums/bucket/psu-tank-behind-scenes-93660.html

 

That could explain why i am so lethargic while on the couch.

well, then i won't worry about it too much. thanks for the help.

 

beautiful tank, by the way.

 

Ph is a function of H+ and OH- ions. The more hydrogen ions you have, the lower your PH, more acidic. The higher the Hydroxide ions, the greater your PH or the more base it is. A neutral PH is 7, think tap water, while acids have a very low PH and base, such as bleach, have a very high PH. Things like the amount of CO2 in the air and conversely in the water and the amount of oxygen in the water/air can affect the Ph. A refugium can also be affected as the plants respire. When you add Alk, you are essentially adding more OH- ions and thus raising your PH. PH changes throughout the day so a small variation is normal and no big deal. A slightly lower PH is also no big deal IMO, but as the water gets more acidic, you may start to notice slower growth in hard corals as the process by which corals grow their skeletons requires a higher PH.

 

so if you were in my situation would you be content with this PH or would you try to raise it?

 

+1 to what everyone said, the best PH is a stable & consistent one, you're def fine.