The recent tear down of a 20-gallon has me considering a terrarium with live plants. This is new territory for me, so I was wondering if anyone has experience in that area.

EI dosing - I expect EI dosing is still possible, the amount of fertilization should be reduced to the actual water content of the terrarium.

CO2 - since the plants have the ability in most cases to grow out of the water I don't believe CO2 is necessary.

Humidity - I believe the humidity in the tank would be required to be high and the need for a glass top becomes necessary. How can we keep the humidity levels high enough? Will a glass top restrict air flow for any kept livestock?

I have some concerns regarding substrate, filtration, and heating. I believe heating cables would be beneficial in this scenario as the water level is reduced and it may be easier to hide the heating mechanism. Would typical substrates such as ADA AS and florite still be applicable? Due to a reduced water level filtration may become an issue. I would like to retain the use of a canister filter such that the filtration media is not contained within the tank proper.

Any websites with photos of others designs?

I am imagining a terrarium with water flowing down a hill side type structure and into a shallow pool of water. Java ferns/Anubias on the hill area and some plants growing emergent in the shallow pool. Maybe a lizard, or frogs for livestock.

Thoughts?

Check out the Dry start HC lawn method without water.

It works very well with any terrarium type plants you chose, you just do not flood the tank if you do not want later on

Regards,
Tom Barr