Hi Carol (big hug!!!) lightly moist, not very soggy, just moderately moist, no standing water. Because there is a plexi lid, it doesn't dry out very much but on one of my tanks, I got the plexi cut at the local Ace hardware and it's too thin so it sags and lifts up the edges allowing moisture to escape. So about every 5 days (or 10 if I'm lazy) I flip it over so that it's bowing upward, takes a few days to sag again. The second tank, I had the lid cut at TAP plastics and got a thicker one. I cut mine to be flush with the inside rim of the tank but am told that if your lid overlaps the edges you won't have the same problems I have had. It's a minor inconvenience. So I do need to add water every so often but not more than once a month and not more than a cup or so. I use a water wand made for the kitchen sink (it is a coil type hose) so I am able to distribute the water pretty evenly.
Haven't ever let it dry out, but did let it get too dry this last week ( I was hot and heavy in a bathroom remodel and in the thick of laying tile) so I neglected all things gardening but it seemed ok, I just added a bit more water and looks like things are doing fine.
I was able to winter over all of my favorite coleus this year because I can get roots in about 8 -10 days and then put them potted up into one of those indoor 4 tier greenhouses.
The concept came from my begonia growing friend who has one from Charley's Greenhouse but it was over $250 so I figured I could make my own. (can't seem to find it on their web site, they may not sell it now)
Here's a peek inside.
