Cleaning the window sills

With temps in the low 50s F, I was happy to continue riding my bike to the greenhouse again this week. The wind was almost zero, and the risk of rain was low. As it happens, while I was at the greenhouse I noticed the rain falling. But, by the time I finished for the afternoon, the rain had stopped and I was able to ride home on relatively dry streets and paths. Yeah!

Adam met me at the door in his office when I arrived at the greenhouse. He explained to me what he'd been working on: an experiment to see which predator is most effective at reducing the population of scale insects and white flies in the greenhouses. He chose three different species of predator. He will add them to vessels containing scale insects and ?white fly?. Then, after some period of time he will assess the efficacy of the predators. The three predators are:

parasitic wasps, Aphytis melinus, that their eggs inside the scale insects
beetles that prey on scale, Lindorus Iophanthae (black lady beetle)
parasitic wasp predators of white flies and their eggs...the scientific name escapes me...

Coordinator A then allowed me to pick from a list of tasks. He said the most important was to clean the aluminum window sills surrounding the walls of the greenhouse. Especially dirty were the sills in the collection rooms 4,3, and 2. I agreed to the task and started the work in room C4 since it seemed to be the room where it was the easiest to get access to the sills. Adam suggested I use warm water with a cap of bleach and a small squirt of dish soap. He said I could probably use a scrub sponge and rag to clean the sill. But, once I started the task in room C4 I discovered most of the sill was out of easy reach, with large dangerous looking cacti up against the sills and outer walls. I wasn't about to attempt moving the heavy clay pots, some weighing hundreds of pounds. So I grabbed an old broom, lifted myself up onto the benches, and dipped the broom into the wash water to scrub the sills from a safe distance. I let the soap and bleach dwell on the sills for several minutes before rinsing off the excess soap with a hose and nozzle set to the "jet" position. I don't think the sills have ever been cleaner since they were installed (if I do say so myself).

Each of the other rooms, C3 and C2, had their particular challenges. Each has a dense collection of shrub-like plants sitting up on benches against the sills. I was able to select reasonably small plants to move out of the way so that I could hoist myself up onto the benches and repeat the scrubbing and rinsing process I had used in room C4. I filled the entire 3 hours of my shift, and then some.
Below are a couple photos of the now-clean sills from rooms C4 and C2:

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