Which material is best for fountains and water features ?
This depends on who your asking, if your asking a retailer who is selling stone or plastic garden fountains you will undoubtedly get the answer that stone or plastic is best and the same can be said for retailers selling any other material the truth is each material has its good points and bad points so here are a few
stone is the traditional material used for decorative fountains, most produced today
are made from concrete which is poured into a mould to produce a dense stone casting that is cold to the touch, hard wearing and
as close to natural stone as you can get without carving from a single block.
usually supplied in sections as they tend to be heavy. Limestone or some other aggregate together with sand cements and pigments will be used in their manufacture, most 'marble fountains' are mainly imported from Italy or Spain and manufactured by adding marble chippings to white cement to produce an imitation marble.
Stone fountains produce a crisp clear water sound as opposed to some other materials such as plastics which tend to damp out the sound, imagine running a tap into a plastic bucket and you can realize the difference in sound quality. If left full of water in freezing conditions stone fountains and water features can become cracked or fracture in the same way that natural stone will, so a little maintenance prior to the winter setting in is required such as draining the fountain or water feature, this is not usually a problem as no matter which type of fountain is bought the pumps will require a clean out at least once a year.
Painted stone- are perhaps a thing to avoid as the paint obscures fine detail of the castings and can hide a multitude of problems such as repairs to poor castings that will crack with the first frost. Painted stone fountains also peel exposing the basic cement colour underneath, these painted fountains are very often of poor quality and should be avoided. Better to look for stone or concrete fountains with pigments or sands added to give the final colour, you can see the raw casting surface and so by necessity are usually of a higher quality than the painted ones.
Plastic water features-
These are generally cheaper as they are mass produced usually in the far east
and imported in bulk.
There is a huge range of plastic/Resin designs available, sometimes under strange material names to confuse the buyer such as 'polyresin' (this is not an actual material but a 'sales' term that covers many types of Polyester and Polyurethane resins, it is often used when the retailer has no idea of what the product is actually made from), in everyday language most people would refer to such materials as 'Plastic'.
These types of garden fountains and water features are usually hollow lightweight constructions which is good for easy handling and shipping but not so good on a windy day.
The all important sound quality will also be low as the hollow construction absorbs the sound of the water.
Plastic fountains will never age well, the paint will fade and peel and the plastic will go brittle with age.
Unlike stone fountains that are cold to the touch plastic fountains are warm to the touch, this leads to greater evaporation so more frequent topping up may be required.
Plastic water features are cheap and if that's your only criteria then that's probably all your interested in.
Glass and mirror water features - mostly available in geometric shapes they tend to be similar to the plastic options available mirror surfaces are usually plastic stuck onto hollow plastic castings, there are some quality products out there but look closely before buying to tell if its a quality product or cheap import
A final point in my opinion and for me this is a big one:
Most products have an environmental impact, first when they are manufactured and then the impact in terms of disposal, between these two events is 'lifespan' how long is the product life. By taking into account these three events you can arrive at a conclusion as to how environmentally friendly they are.
Concrete has an environmental impact if fossil fuels are used to make the cement, concrete is however made from natural materials, properly cast concrete can have a useful life for potentially hundreds of years, indeed some concrete structures created by the Romans are still standing.
I am not saying that your stone water feature is going to last several hundred years but it might!
After its useful life as a water feature is over it is still basically stone, this can be used for a variety of uses from making a rockery to hardcore for foundations or simply crushed and reused as an aggregate. Eventual disposal is relatively simple since it will eventually degrade back to its original natural component parts earth and rock.
Plastic/Resin: Cheap resin garden products from China are not environmentally friendly, aside from the carbon footprint of the 4,000+ miles they travel to get here the toxic chemicals used in their manufacture can cause major pollution problems for wildlife and the environment. As a liquid the material produces toxic gasses, the disposal of waste products from manufacturing needs to be carefully controlled to avoid environmental damage and pollution.
They have a relatively short life span once exposed to the sun (UV). The main visible effects are a chalky appearance and a color shift on the surface of the material, and the component surface becomes brittle. After they have become brittle, broken and faded they will clog up the environment as waste possibly forever, never fully degrading.
It is possible to recycle some grades of resin but I don't know of any attempt or classification that would allow for the recycling of resin water features, to be able to recycle something it has to have a system of material classification in place and be technically possible, so after only a few years of use in your garden landfill is the usual destination for these products.