strange tap water pH question

billsreef · #1 03/13/2002, 11:09 PM

Hi Randy,

Had a regular custome of mine from the LFS come in with a rather interesting observation. She's been having problems maintaining pH in her FW tank, so she tested the water out of her tap and it was about 8. Where it gets interesting is that after letting it sit for several hours in a plastic bucket, only used for her tanks, the pH had dropped to around 6. Usually the town water around Long Island is buffered with lime and can be expected to settle on a pH around 7.2 to 7.8 after the dissolved gasses have hit equilibrium with the atmosphere. Any ideas on why normally hard, limed, water would drop so low after sitting

Randy Holmes-Farley · #2 03/14/2002, 08:08 AM

All I can think is that there wasn't much buffering in that batch of water for whatever reason, and CO2 from the air drive down the pH. In pure water, the pH can drop to the mid 5's from CO2 alone, so the result is resasonable, although it may deviate from what is normally seen for that water source.

billsreef · #3 03/14/2002, 09:46 PM

That makes sense. Generally they add lots of lime to the public water supplies here. However someone I knew that worked for the water authority told me that the quantities could vary tremendously depending on who was adding the lime that day and what sort of mood they were in

Randy Holmes-Farley · #4 03/15/2002, 08:26 AM

However someone I knew that worked for the water authority told me that the quantities could vary tremendously depending on who was adding the lime that day and what sort of mood they were in

Well that gives you a warm fuzzy feeling inside, doesn't it

billsreef · #5 03/15/2002, 10:27 PM

Makes me glad I'm on well water