Backyard Aquaponics
A place to discuss aquaponics

I can't find anything for or against reusing the regent after calibrating. I says to use the regent within 4 months of opening, but nothing about whether it can be used more then once. I've been using it weekly or so to calibrate my meter. It seems to always drift up about .10-.16 during that time. Not trying to be cheap, but don't want to throw away something that is still good.

If you are talking about pH standard buffer solutions in a 500ml bottle, yes you can keep using them, so long as you haven't contaminated them. I've been using the same standard buffers for over 18 months- I make sure the sensor is clean and dry before putting it into the buffer.

Also avoid letting the buffer sit around where it can evaporate.

Thanks guys, I thought it would be ok, but dumped the first few. I clean the meter before and after calibrating.

I always just pour a small amount into a shot glass, use it to calibrate the meter, then dispose of it. The amount used is pretty small, and it prevents any contamination issues.

Another way to go is use it and put it into a different bottle then keep re-using but out of the 2nd bottle. This keeps from contaminating the rest of the original stock buffer.