Table 6.

Percentage error generated when using control data standard curve to estimate chlorophyll concentration in the presence of environmental interference^*.

	Total chlorophyll		Chl a		Chl b
	% error at max	% error at half max	% error at max	% error at half max	% error at max	% error at half max
Low volume	4.3	4.6	3.9	4.4	5.1	5.2
High pH	8.8	5.2	12.9	10.2	0.1	−4.8
+1.5 ml E. coli	14.9	21.1	17.8	25.3	7.9	11.4
+0.325 ml E. coli	6.4	10.7	8.1	12.4	2.4	6.2

^*Percentages are calculated at the maximum measurable and half maximum measurable chlorophyll concentration from the control data standard curve.