Reptile & Amphibian Forums

I volunteer at a local Nature Center in the Los Angeles area. Recently, I was asked to help out in improving the habitat for the 2 toads, one tree frog and one rough skinned newt, all native. They live in a 2'x2'x4'tall glass enclosure with sliding doors in the front. There is a 6-8 inch space from the bottom of the cage to the bottom of the doors. It appears to be silicon sealed and watertight. For the past several months, I believe they have been living in substandard conditions with no cleaning or other maintenance. The substrate from bottom to top.....blue plastic bio balls, non-woven fabric, rocks, jungle something bedding. A lone pothos clings to life in the corner.
The substrate has been kep so moist that there is a layer of water, making the front of the habitat swampy. No pool of water was provided and my suggestion of a filter deemed unnecessary due to the bioballs.
The people who set this up are no longer with the park and the existing staff members like how I have set up other animals and insects.
I was thinking of something like one of the following:
http://www.reptiledirect.com/tetra-viquarium.aspx
or
http://www.futurepets.com/cgi-bin/FULLPRES.exe?PARTNUM=TM19524

Knowing next to nothing about amphibian keeping long-term, I would like some input. The park, I'm sure, would like to go with the lower cost setup. How would you set up a vivarium for these three species? Would you use those waterfall filters or something else?

Things to consider:
1. Most of park staff knows less than I do about the toads,frog and newt.
2. Maintenance needs to be minimal. It is likely to fall upon us volunteers on weekends.
3. Setup cost needs to be reasonable
4. Cost of maintenance supplies, like filter media, needs to be low. A great setup is no good if they won't buy filter media as needed.

I appreciate your more experienced input.

What I would recommend is setting up a mini-wetland filter. I use these for all ampibians and most reptiles. It is 100% self sustaining other then topping off the water levels once and while.You can't buy a mini-wetland filter you have to make one. The idea behind it is to cycle the water in the same way a wetland does using live plants and soil. You will need some plastic egg crate, which is found in the florecent lighting section of any hardware store, some window screem and a powerhead or fountain pump. The fountain pumps are actually designed a little differently and work better. The basic idea is use the egg crate as a platform a few inches above the bottom of the tank or enclosure underneath the platform you have biobeads or lava rocks and your power head. on top of the platform you have your soil, moss, water fall, and live plants. In the soil add earthworns leaflice and other such critters as you would naturally find. Make sure you create access door so you can get to the power head when you need to. Plant as many plants as you can, they are critical to the operation of the filter. The live plants will grow roots throughout, above and below the platform. they will add oxygen and remove both nitrates and nitrites, heavy minerals and other polutants. the biobeads and lava rocks will grow nitrosomas bacteria that will convert amonia and nitrites into nitrates. The end result is a full cycle that needs no attention at all other than to clean the viewing glass, and keep the water topped off. I have used these with water dragons, anoles, poison dart frogs, newts, toads, and various frogs. My longest running system ran for 12 years without maintenance.