Hmmm, and African daisies are sold as perennials here in contrast to the "annual" gerberas. Ironic. Personally, I like both. African daisies come in some gorgeous colors. I don't care for the foliage of the gerberas at all, though. But I like the blooms enough to overlook that.

Was the toilet installed as part of a bathroom remodel? Did you confirm that the water lines are hooked up to the water treatment system you have? Just another item to look at if you don't get assistance from the manufacturer. How are the sinks in the master bathroom? Do you have staining in those too? I have no particular advise about the cleaning except that you may have damaged the finish with the pumice stone and magic eraser because this is a hard abrasive. This may make it harder to keep clean in the future Good luck!

What is the model number. There are quite a few Gerber Viper toilets on the Map test list. Most are rated at 800 grams per flush but several are 350 so just make sure you don't get one of those!

Fungus isn't crystal-like. Is it on the stems close to the soil? That usually means overfertilization, which is common in potted plants. Tibouchina may have gotten root rot. Did you wash the roots off thoroughly and dust them with fungicide before you repotted it? The rot is in the soil, so if you put the garden soil into the pot, it's just going to go on killing it. Here's what I do: Wash the roots off thoroughly Remove as many dead roots as you can. Soak the roots in a water/peroxide mixture overnight to kill the fungus and oxygenate the plant. I put about 8 ozs of peroxide for every 2 gallons of water. Dust the roots with fungicide (rooting hormone or cinnamon will do - yes, the spice cinnamon. Replant in a mixture of 3 parts clean potting soil and 1 part perlite. DO NOT FERTILIZE. Keep the soil moist, but not wet. Stick your finger into the soil up to your second knuckle. If it's dry that far down, water it. If not, leave it.