<https://barrreport.com/threads/how-to-use-a-ph-drop-checker.2624/>
<http://schema.org/articleBody>
"hi, I just got my ph drop checker. to be true, this is not what I thought. \r\nwhat I have is the glass \"checker\" (dont know how it's call), a cheap chart that tells me what colour match each ph level and a bottle of co2 test. \r\nthey say: add 5..."
<https://barrreport.com/threads/how-to-use-a-ph-drop-checker.2624/#post-15003>