iI would toss out a guess at the technology used to count pods:
Coulter particle counter
I did get a free shipment and the visual count looked weak in my batch too. That said, counting really small pods isn't a visual activity but it can be done (estimated) using a good microscope and a thingamagig that indicates the area of water you are counting from. If the visual stuff is good (phyto) then I would suspect that the non-visul is good as well, but this isn't verified by me. I trust and if I suspect something was wrong I would find a scope and count a few cells.
I believe the culture is supposed to seed your system so that they might become self sustaining there. Hope it works out for you.
assume they just do it by weight or something along those lines.