Sorry for the bad picture, since I am poor and cannot afford decent microscope! But we can see, that the zooplankton is eating the smaller greenalgae, but the spirulina is too big to eat.
So why I want to contaminate it like this?
First, the econiche is now reserved: which prevents weedalgae etc.
So the point is, that we can choose the contamination that in fact: is benefit in many ways.
First, as you know aeration or other mechanism is important for mixing the culture: so that oxygen will release to atmosphere more efficient. Also CO2 can be provided through aeration.
The zooplankton, is a minidevice for mixing the culture. As you can see, they move alot: mixing the culture.
Also, they produce CO2 and use oxygen: and as they eat smaller algae, the zooplankton excrements will be nutrients also to spirulina.
The problem is to balance this miniatyre ecosystem, that the spirulina will remain dominant.
In the end, we can just collect the whole biomass as fisfeed since many fish live solely on zooplankton like Coregonus albula which is also perfect fish to aquaponics since it is small and comes ready just in couple months – and you can eat it as whole, just fry it and it is very crunchy, one traditional food here in Finland!