PH problems

[Christianreefa]

Hello everyone i have had my tank cycling for around 1.5 weeks now, my LFS has tested my water in 2 occasions. The first time NH4 was 0 as with nitrite nitrate, Ca Mg and PH was low so they gave me a buffer called aqua vitro 8.4 for reefs i followed the instructions and my ph rose to around 8.2 but slowly but surely dropped down to around 7.6, being a noob i kept adding it until my alk went up to around 15dkh. Then on my second trip to get my water tested the results said my calcium was 360ppm Mg 1440 but ammonia was 0.2 and N02 0.4 im fairly confident the ammonia spike was to do with the recent dry rock i had added 4 days earlier. They must have had some organics on them. Ph still low but alk still very high at 16dkh and PH low at 7.6. I did a huge water change bringing my alk down to about 10dkh and have pointed my power heads up and opened windows and even increased the air input on my skimmer but PH during daytime goes up to a maximum of 8.1 and 7.6 at night. Is this to do with the tank still cycling? I have heard products from cycling produce acids and CO2. Is it just the case of waiting another couple weeks?

[bertoni]

[welcome]

A low pH reading is common for tanks during the cycle. I'd do a few water changes, maybe 15% or less, if I had the energy, but there's a lot to be said for waiting. The alkalinity is at 10 dKH now, which is fine.

If the pH stays very low, below 7.8 or so at night, you might want to check that the skimmer (if any) is properly tuned, and make sure that the water surface is free of any film. A good rolling action on the surface is ideal.

The pH rises during the day because photosynthesis consume carbon dioxide from the water column. That range is a bit wide, but not that unusual. Mostly, I'd just wait.

[thegrun]

Out of curiosity how are you measuring your pH?

[ReeferNoob4ever]

All that 'decay' is putting Co2 in your tank don't worry. After your tank cycles and you have some P04 and N03 run an algae reactor 24/7 that will stabilize your pH.

[Daddi0]

I wouldnt worry about anything on a tank that young. Time and patience.
Cheers! Mark

[mcgyvr]

Stop worrying about PH..
Throw away your PH test kit and toss the buffer into the trash.

PH will be what its going to be.. Just leave it alone and never think about it again..

Worrying about PH is newbie mistake #1..
Your current PH of 7.6-8.1 is TOTALLY FINE..

Again.. stop worrying about PH..