I watched this happen. It was amazingly stark in its simplicity.

I'm an aquarist. Have been since I was 6. And the last time I set up a giant tank (72 gal) I was using the filters that everybody loves. They're expensive. They circulate poorly, however. In short, they suck.

One of the problems with poor circulation is you get anaerobic areas in your tank - where cyanobacteria can spring up. It looks like algae, except it's an unnatural green. It also stinks - it smells like spinach that's been in the fridge too long. So I asked the local fish store what do.

"Hit it with a half-dose of erythromycin," they said. Erythromycin is a panacea in freshwater aquaria. It cures all sorts of things. So, okay. Whenever we see cyanobacteria, we hit the tank with a half-dose of antibiotics. Probably happens once, twice a year. This went on for three years.

Year 4 my entire tank was taken down by thermonuclear crud that absolutely, positively would not respond to antibiotics. Killed every fish in it. It occurred to me then that:

- I was solving a circulation problem with medicine

- I was following the advice of people that never kept stock more than a couple weeks

- I had been diligently and vigorously been breeding antibiotic-resistant bacteria for three years.

So I ditched the Eheim, cleaned out the tank, and never visited that fish store again. Now, when I see cyanobacteria in a tank, I re-arrange.

I put a social worker through grad school. She ended up at a hospital dealing with people bouncing out of nursing homes. One of their primary reasons for bouncing? Medicine-Resistant Staphylococcus Auraeus (MRSA). You get a run of that in your nursing home and it's like cyanobacteria in your tank.

My daughter goes to daycare in near-squalor. There's a parrot, chickens, rabbits, and lots and lots of dirt.

And I like it that way.