Ph too high!

[BruceLeeroy]

Help, my water is at 78.5 degrees, ph is 9.2 on a calibrated Hanna pen, sg is 1.024, using RO and IO reef crystals. The tank is just into its algae bloom after 6 week cycle with dry rock and Microbakter 7 and a dead shrimp change for 10 days. I added a snail (trochus) and a hermit to get started on the algae and diatoms and leftover food from ghost feeding.

so additional note. I was looking up fixes, marshaling my forces of vinegar and lemonjuice ready to bravely sally forth and save my snail and crab... and decided to calibrate my meter. A dip calibration solution of 7.01 read at 7.9. After recalibration the tank is at 8.2.

I’ll make this post anyway for learning porpoises as to how Easy panic and noobishness can screw things up. ALWAYS CALIBRATE IF READINGS ARE WEIRD BEFORE TRYING TO FIX IT!. I should tattoo it on my forehead.

 

[Larry L]

ALWAYS CALIBRATE IF READINGS ARE WEIRD BEGORE TRYING TO FIX IT!

This 100% ! Glad you caught it before anything drastic happened.

 

[chipmunkofdoom2]

I’ll make this post anyway for learning porpoises as to how Easy panic and noobishness can screw things up. ALWAYS CALIBRATE IF READINGS ARE WEIRD BEGORE TRYING TO FIX IT!. I should tattoo it on my forehead.

If calibration doesn't fix the issue, search the Chemistry forum or ask a question here. There are many posts in the chemistry forum where test values are so out of the ordinary given the circumstances that the only possible explanation is testing error.

This was one of those cases. Due to the strong carbonate buffer system in seawater, it's very rare for pH to stray outside the 7-8 range. It's possible with large additions of powerful acids or bases, such as HCl or hyrdoxide solutions, but still rare.

Another such case is that of high magnesium consumption. Frequently, a poster will ask why they can't keep magnesium stable. They dose up to a certain value, test to confirm, then overnight they record a drop of about 25 - 50 ppm. Magnesium consumption on this scale is not possible under normal circumstances in reef aquaria. If your tank consumes about 0.5 dKh of alkalinity per day, it will only consume about 37 ppm of magnesium over the course of an entire year. Testing error is the only likely explanation of the observed drop in this case.