I use Cryptanthus for decorative value. My frogs don't utilize them however. They don't hold water like some of the other bromeliads. I worry more about some of the bromes that do hold water, but also have little prickles on the edges. Neither my D. galactonotus nor the D. leukomelas seem to be bothered or injured by these, and both utilize them for sleeping, sitting, hunting and soaking in the axils. Maybe they are simply aware of the prickles and know how to avoid them. I hate to make this kind of statement, because tomorrow one of them may sustain a puncture, even after a couple of years of living well with a few rather prickly plants. I don't use any of them that have the prickles except for decorative Cryptanthus in the arboreal frog tanks such as the imitators or pumilios. This is mostly accidental rather than thought out.
As far as the pesticide, fertilizer issue goes, I set up any new tank months in advance because I like terrarium plants nearly as much as I do the frogs. Then I decide what frogs to put in them. With the additional month or two of quarantine and nursery tank set-up for froglets, there just isn't much left to harm them in the permanent tank. The water features have been circulated for months and it's all been thorougly misted and sumped out. Fungi, mushrooms and the soil insects are established or have been controlled if they don't seem beneficial. Maybe this is too simplistic and I don't worry enough, but so far (cross my fingers and knock on wood) it has worked well.
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Patty
Lost River, Idaho
4 D. auratus blue
3 D. galactonotus pumpkin orange splash back
5 D. imitator
4 D. leukomelas
4 D. pumilio Bastimentos