Originally Posted by huma-huma
Wait a minute. Fresh oxygenated air will DROP the ph. Put some tank water in a ziplock, seal it, and leave it alone for a few hours. The ph will be high. Let it sit with fresh air for an hour and itll drop. Anytime you expose water to fresh air, the ammonia can spike, causing the ph to drop. <7 is acidic, >7 is alkaline
Please take some time and read this article....
Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com
"High indoor carbon dioxide levels can also lead to low pH problems in many tanks. Respiration by people and pets, the use of un-vented appliances burning natural gas (e.g., ovens and stoves) and the use of CaCO3
reactors can lead to high indoor carbon dioxide levels. The level of carbon dioxide can easily be more than twice that of exterior air
, and this excess can substantially lower the pH
. This problem is especially severe in newer, more airtight homes. It is unlikely to be a problem in homes like mine where the wind can be felt blowing around old window frames.
Many aquarists have found that opening a window near the tank can significantly raise the pH within a day or two. Unfortunately, those aquarists living in colder climates cannot comfortably open windows in the winter. Some have found it useful in these situations to run a pipe or tubing from the outside to the air input of a skimmer, where fresh, exterior air is rapidly mixed with the tank water."