Here, we fix the initial value of Ps (Ps0=0.1) and explore the behavior of the solution for different initial values of V and Z. In *this note*, we looked at time series for Ps0=0.1 and Z0=0.04 or 0.05. in the first case, viruses have to be in high quantity initially to kill the bloom. In the second case, the presence of viruses even in high quantity does not change much the dynamics, which is that of no bloom.

We see this in the upper-left panel of Fig. 1. Most of the maximum Ps is determined by the value of Z0 not the value of V0. Only when Z0 is about 0.04, do we see a significant change when V0 is increased, but this change occurs only for large values of V0 (V0>0.7). Finally, as in previous cases, final values are independent of initial values and is fixed by the Z-P dynamics.

To produce Figs. 1 to 4, `manyruns_5.py` in `RESEARCH/MODELISATION/marine_viruses/current_version/runs/run_001` has been used and were plotted with `plot_analysis_many_runs_5.py` in `RESEARCH/MODELISATION/marine_viruses/current_version/runs/run_001/analysis/manyruns_5/`. Everything is on the main `ipu1` disk.