EXO chlorophyll readings show excellent linearity on serial dilution of a surrogate solution of Rhodamine WT (R2>0.9999) and this should ensure relative accuracy of field chlorophyll readings, i.e., a chlorophyll reading of 100 units will represent twice the algal content of water with a chlorophyll reading of 50 units. Also, EXO chlorophyll readings show very low interference from turbidity, allowing for more accurate determination of algal content during rainfall events which release both sediment and algae into the water. The EXO chlorophyll sensor also exhibits very low interference from dissolved organics, increasing data accuracy.