Those filters remove sediment, chlorine, and organic molecules, but do not have the capacity to reduce dissolved solids, which can be problematic for plants.

If your terrarium can drain, then it may not be a problem. But if not, then those minerals will accumulate until the plants can no longer absorb water.

If you need a lot of pure water, an RO filter is the best option. Otherwise distilled/rain water is the way to go.

I have used both and I find that in my "show" tanks, distilled works best. I hate cloudy or spotted glass. Grrr!

In the 143 other tanks, breeder tanks etc I use 2 week old/treated tap. I've never had an issue with the frogs or the plants not growing and usually bring bags of clippings as gifts to the expos or get togethers I frequent.
Mac

True! On my first terrarium, I had nasty water marks and had to soak it in CLR for over a day. It worked really well.

From now on, distilled only! It's worth it for the health of the plants and keeping the glass beautiful!

Hi
Was reading your post on the irrigation forum. Looks like you got my answers here lol. I generally use RO water
because of the price . I can get it at the grocery store for 30 cents compared to 70 for distilled .
A home system would be great but not worth the expense unless you use a lot of water. Does make wonderful coffeee though lol gary

Like Gary, I use RO water. Living in an apt makes collecting rainwater a no go. & like Gary, I can get RO water for 30cents/gal at my local grocery store .... huge savings over distilled.