Quick question regarding the information on the PH level of the water. My tank is half water/half land (split bottom). The ph balance is running around 7.0 to 7.2; all water added is treated with the appropriate amount of reptisafe water conditioner, and then filtered continuously through a tank waterfall (that has insert filters inside). So, from the article (thanks by the way!), I know it's bad to have a ph level lower than 6.8. What's the high range that I should be on the look out for?

Thanks!