Re: What are the best broms for Darts??
Hmm. The only bromeliad I have from Lowe's has survived a couple of years, but it's in an Exo Terra tank from my primitive vivarium-building years that still has its original screen top attached. In other words, very high ventilation.
I have kept Neoregelias alive in pretty low ventilation, but not no ventilation.
I'm concerned about your substrate setup. It's good that you are going to use a barrier, and hydroton is probably an improvement, but having a saturated substrate sounds like a problem. I don't know nearly as much about frogs as the other users here, but that doesn't sound like a great environment for frogs to live in. I would consider making a tube through the substrate to siphon water out of the drainage layer, or drill a hole for automatic drainage through a bulkhead + tubing.
It would be a good idea, if you have been putting plants into your setups without cleaning them up, to wash off the dirt / substrate that they were in when you bought them. This seems to me to be truer with plants from big stores like Home Depot / Lowe's than from dedicated, small-scale businesses.