I forgot to mention that I have duckweed floating in the dish as well.

What? How does a plastic container leak? I'd say the only way is that there's a hole in the container, so just replace it with a new one. Plastic isn't exactly porous. . . you could also coat it with some black silicone (GE type 1, I believe, available at HD and Lowes and similar stores, 100% silicone) to get rid of the whiteness. You could even embedd some rocks (like aquarium gravel) or something into the silicone (use a really thick layer if you do this) for greater 'natural-ness'.

I also have a 5 gal CP tank, and I love it! Aren't they just the perfect size for a cute little CP garden? I also have a VFT in mine. Used to have a ping (died, my fault), and I have a fern (quickly getting too big) and a nep (slowly getting too big). I want a sundew and another ping or two. =) A little pond with duckweed is a good idea! Bogs do usually have some standing water!

That is what is SO frustrating sahoyaref!!! I initially used the lid to the the terrarium box the plant came in when I bought it. That one had the same problem. So thinking it was leaking... I switched to the sour cream container. Same thing is happening. I've checked it for leaks and there aren't any. I thought maybe something is wicking it out since sand and perilite is pourous and provides drainage. But the sides are smooth plastic and nothing is dipping into it. I've even tried raising it higher than the surface soil of the terr. I really want to keep this looking like a bog:) And I love my duckweed...super cute!!! Any other advice???

That is too bizarre! I can't imagine what would be wicking the water out, especially if there is nothing hanging into the water, like plants or moss or a bit of soil. Could it be that the water plants are the problem?

Well, I'd say it was plant transpiration or just cellular growth since it is doing so well. But, the water doesn't seem to decrease below this level. Last night I tried putting moss around the dish, to at least keep the water more towards the surface and not drain through. That actually slowed down the water movement. But this evening... back to the same level. If the level was the same as the soil around it then I would say "fine it's just balancing itself." But it is lower! urgh! I'm wonderering how big the miniscus is. Purhaps it's wicking itself...but the duckweed it breaking the surface tension right? Or is it...hmmm. Follow my manic thought process? Any other thoughts?

The miniscus really isn't that 'big', so I highly doubt that it's wicking away unless you're filling the container to within 1-2mm of the top. The duckweed wouldn't really be breaking the surface tension. That's how it floats on top. Plants also don't really have sharp edges. I'd guess that it's just the plants using up the water. Duckweed does grow insanely fast. Also, is the top of your tank totally covered? If not, evaporation could be the answer.

The top is covered. I don't think it's the water plants, since the plants don't "drink" any water past that level.

I don't know anything about growing plant in a terrarium but you could try on your kitchen counter to sit the bowl in a larger glass dish with some folded paper towels under the bowl. Then fill it with water and if the paper towels get wet, then you know it's leaking.

Lucille2

Try a false bottom setup.