HydroRocks is the one who's spent the years (and years and years) doing the slides and stains.
If you let your eyes adjust you can see mad life in this 48 hour tea with fish hydrolosate and molasses.
No foam on this batch.
I've had the foam discussion with many people, for some reason a lot of people associate foam production with microbial life. My experience with two things--tea and foam fractionation--tell me this isn't necessarily the case.
Foam fractionation is actually one of the early forms of chemical filtration. A basic foam fractionator (aka protein skimmer) is usually a tall container for the water column that has an inverted funnel at top with a collection cup (the taller and thinner, the better) where superfine bubbles are mixed. At the top of the column a foam forms, and, especially if it's a good 'dry' foam, is pushed up through the inverted funnel into the collection cup where it can be removed.
So, what's making the foam and being collected? Dissolved organic compounds, aka DOCs. Why does foam fractionation work? Because, DOCs are (usually) polar, in that they have a hydrophilic 'end' and a hydrophobic 'end' (of the molecule). The hydroPHOBIC end sticks to the bubbles, and is thereupon carried up the water column, where it contributes to making the foam.
Wanna know what one of my favorite jobs at the Long Beach Aquarium was? Cleaning out the giant protein skimmers. About 10'-12' tall, 2.5' diameter, the first time I worked on them I almost fell in.