Physico-chemical analysis of the samples

• First sample


A decrease in the volume of the samples, through evaporation, of about 50% in a period of 45 days, with a significant increase in the cell density during the experiment was found
The cell colonies were observed to have increasing sizes, throughout the 16 weeks of observations, and a higher number of cells than initially
During the 5 weeks of sample analysis there was an increase in the chlorophyll concentration by about 20% in the samples exposed to light and with the addition of fertilizer (batch 1) compared to the control samples - from 0, 2 at 0.35 μg chlorophyll/L. Only 5% increases were seen in light-exposed samples
To determine the change in chlorophyll concentration, GPI (green pixel intensity) was also calculated using a colorimetry application, starting from a value of 0.2 of the G/R+G+B ratio up to 0.35 in the samples exposed to light

• Second sample

The GPI was a maximum of 0.48 (correlated with a maximum concentration of 0.36 μg chlorophyll/L) in fresh water and 0.03 in seawater (correlated with 0.01 μg chlorophyll/L)
The cell density in the fresh water sample evolved from 230 cells/L to 330 cells/L in about 3 weeks, and in the sea water from 10 cells/L to 20 cells/L, in the same interval
Chlorophyll concentration increased from an initial 0.20 μg chlorophyll/L in fresh water to 0.36 μg chlorophyll/L, and for seawater, the concentration remained very low at 0.01 μg chlorophyll/L. In control samples, the concentration was a maximum of 0.18 μg chlorophyll/L in fresh water and remained constant at 0.01 μg chlorophyll/L in seawater
Dissolved oxygen in both types of samples had values from 7.9 to 8.5