Two Questions - water lettuce and liverwort

I have two completely non related questions.
First, I just purchased a water lettuce for a newt tank from a home improvement store. I forgot to ask when I purchased it if there may be any chemicals in the water like fertilizer or pesticide, anything that may harm my newts. I would doubt this as I would think these plants would be safe to add to a fish pond, but I figured I would leave the lettuce in a bucket and do water changes every day for a few weeks, just to be on the safe side. Does this sound neccesary, and if so will a few weeks of water changes be sufficient?
Second question, on another plant I purchased there was some liverwort (I think Marchantia sp) in the pot. I really like the looks of this ancient plant and was thinking it would be nice to keep, but I have no idea what conditions it needs. The soil was pretty moist so I think that must be important, but don't know about light conditions, temp or humidity. I would really like to culture some and transplant it to, what else, a newt tank, like for a floating island or if it would grow on wet wood sticking above the water surface. Does any one know how to grow this plant/what conditions it will need?
Thanks so much for any input

Hi Heather,
I cannot comment on the liverwort because I have never tried to grow any however water lettuce does best in direct sunlight. I tried growing some under standard fluorescents years ago and it faired poorly, eventually making a mess of the tank before it died. I have grown it outside in a small pond where it did so well that it soon had to be weeded out on a regular basis. I would imagine that the amount of high output light required to successfully grow water lettuce indoors may either be too bright and/or put out too much heat for your newts' comfort.
Chip

I think that soaking the water lettuce for a while is a worthwhile precaution. I don't know about pond plants, but mass-produced houseplants are usually treated with all sorts of chemicals.

Thanks for the comments. Dang, I thought I had read here in a few threads that various people had used and had good success with the water lettuce in their tanks. So I guess after I let it soak with some water changes I will put it in an empty tank under a flourescent bulb and see how it does - I sure don't want a mess in my Cp or Maa tank. I really appreciate your input,
Heather

If you can keep it outside in a bucket of water and soon you should have quite a bit of it, then you could experiment with some in one of your tanks. I was just sharing my experience. Who knows, maybe it will do better for you. If it starts breaking down then you can always pull it out.
Chip

Hiya,

Re: the liverwort - these plants are ideal for the humid atmosphere of a terrestrial or semiaquatic setup. Grow them on moist bare soil. They may also grow on wet wood as you suggest, but it may be hard to get them to attach.

Not sure about the water lettuce - it seems like it would get a bit big / invasive for most aquaria anyway, even if it did survive. I have seen them grown in zoo / botanic garden setups in glasshouses - they seem to need plenty of heat and light to thrive.

Tristan