Following initial titration studies, the pH was adjusted to the
designated treatment level by slowly adding 0.1 N sulfuric acid to
each enclosure
During this process, water inside each experimental
unit was gently stirred and pH was monitored to ensure a
uniform pH at various depths
Throughout each experiment, pH
was monitored twice weekly in each enclosure using a calibrated
Hydrolab Quanta (Hach Company, Loveland, CO, USA) or YSI 600
XLM multiprobe (Yellow Springs Instruments, Yellow Springs, OH,
USA)
If needed, pH was readjusted to its designated treatment
level following the aforementioned procedure.
In addition to two
weekly discrete pH measurements in each enclosure, YSI 6600
XLM multiprobes were suspended in the middle of one randomly
selected enclosure for each treatment level and set to continuously
monitor pH at 15 min intervals throughout the entire study.