Standard fluorescent ballast. T12 bulb or whatever the large diameter, old fluorescents are. Nothing special
Hanging outboard filter
Schultz's aquatic plant soil
Malachite Green...trace present on once light brown sponge on filter intake. It dyes certain materials. I found my air stone tubing and sponges were dyed.
Quarantine tank. The angel got some sort of parasite. It went blind, had a bloated stomach, and might have had fin rot. I fed it through a pipet for 4-5 months. Not a good time. It was on the tank bottom one night still breathing, and I decided to euthanize it.