Wow..such a nice specimen. Gonzer,how do you take care the plant, especially watering, because I've some problem with my bush-type T.tectorum. Their trichome become disappear.

Stephania, it gets watered maybe every other month with absolutely no fertilizer. Coming from such high altitudes, tectorum grows in what is called an oligotropic environment, meaning nutrient deficient. They've adapted to surviving on the barest of nutrients in the atmosphere. If green is showing consistently on the leaves it's simply getting too much water or misting. So almost forget about watering these plants unless your temperatures are constantly in the 80's and 90's.

Xero's are that fond of too much moisture either Stephania. They won't show the effects of too much moisture like tectorum due to their thicker leaves. Often times the only clue you'll have that your Xero's been exposed to too much water is that it will simply fall apart while still looking healthy. The less moisture for a Xero will result in tighter curling of the leaves.

Thank you for your informative post, Gonzer. I certainly will apply your advice for my xeric species Till. watering. And one question, I've heard some one recomend that we should give water all the gray/white coloured Till. only in early morning, is that right ?

Here's an article on Tillandsia respiration that gives some information on the reasons for early-morning watering.

Here is a link that might be useful: Respiration and watering