So I have been running my 16X16X24 26 gallon natgeo vivarium for a few months but I'm trying to figure out how much bedding do I change and how frequent. The live plants are 4 arrow plants 8 white ribbon in clusters 1 dracenia Anita and a yet to be identified dracenia. The exoterra bedding is around 3" deep with a 2" drainage layer of sea chems fluorite with 2 25W bulbs over head to add some heat and a fish cfl for uvb light. Is it okay to let night crawlers roam free with him to help the plants grow and provide him with food or is that too much for the size tank too pull off?