Tillandsia makes pups after blooming, but some of them gradually decrease their size at each generation. This is because they bloom even if their size is much smaller than the original foliage. First, I was happy because I could have more space to cultivate others, but, second thought, it does not seem healthy condition. The worst case is Till. ionantha var. Maxima, and its size decreases 1/3 of original one. This may be because I have never given manuer. Pups of other species bloom after growing upto the same size of original ones, although it grows slowly.