just thought id post an update regarding the situation i had with the tiny white worms i had infesting my waterfall.anyway,like i was told by patty and others,they cleared up on their own.i have no idea how they got there but i suspect,since the waterfall was partially submerged in soil,and the crack that exists so you can take it apart was under the soil line,they just crawled in when the soil was saturated and bred in there.there was no food in the water so they existed for a bit by consuming the dead worms but eventually they all died.just thought id post an update just in case anyone else experiences these and worries like i did.now i have a second question.i have not yet introduced any frogs but i feel my vivarium is now doing well and is balanced so i am thinking of adding a pair.i am concered about the design of the waterfall and am looking for suggestions from anyone who uses or has used this(exoterra waterfall) if you are familiar with this,you know its a self contained waterfall with a small space in the rocks where the water flows into the bottom.plenty of space for a frog to squeeze in there and im afraid he will not be able to get out.any ideas?? i have the larger one by the way and im not familiar with the small one or if there is a similar hole for frogs to get in.if one was to get in,it goes right to a deep pool of water and i am afraid my frogs will die if they cant get out.thanks again/