This is the setup I use for my banded newts. It's outdoors, with acrylic covers to keep birds from eating the newts, and the newts are kept in the tank year-round. Filtration is provided by a an airlift running off of a central distribution manifold and pulling the water through a gravel-filled compartment. The gravel has a layer of cobbles on top to prevent it from being ingested by newts. The air pump is in the garage, and delivers air to the manifold via a garden hose, which is connected to the pump at one end and the manifold at the other with a liberal application of hot-melt glue.
The tank has a terrestrial section formed by a plastic box weighted with gravel and filled with coconut fibre. The side of the box near the base has been drilled and a length of 4mm PVC airline has been passed through and hot-melt glue has been used to seal around the airline to make the plastic box watertight again. The airline then connects to a similar piece of airline that passes through the wall of the overflow pipe in the aquatic section. This system allows the terrestrial area to freely drain when it rains, so it doesn't fill up and become waterlogged.
The plastic box rests on a pair of small plastic food containers which have had large holes cut in them to allow newts to pass in and out of them. This provides shelter for the newts, and also avoids the possibility of an anoxic region forming under the plastic box and poisoning the newts through a release of hydrogen sulphide gas.