Here is an article to show you how to work with Mother Nature and create a pond that is both beautiful and sooo very cheap! I've been ponding for a lot of years and one thing I always made sure to accomplish was "do it as cheaply as possible". Well, what do you expect? I'm a poor redneck!
To create a pond you must first locate a liner. It doesn't matter what color it is, even if it has purple elephants on it. In time it will be covered with algae and silt so you will not see the liner itself. If the color of the liner bothers you, cover it with black trash bags. I've used everything from sturdy trash bags to water bed liners for my ponds. Pools are great too. If it will hold water, then you can use it (unless it isn't fish safe). Some people even use rubber roofing liner. You must first rinse this liner thoroughly though to remove the powdery residue on the surface. I feel it important to add a disclaimer: some people caution this liner can harm your fish, though I truly doubt it. Do your research and eventually you'll draw your own conclusions about what's safe for your fish.
You can also layer silo cap as a pond liner. It's cheap and people claim it works. Just remember, some liners won't last for many years so choose carefully one that you can get the most use out of. If it's a small pond then it's no big deal to have to redo the liner on a yearly basis. Though, this does mean having to cycle the pond again.
Getting plants for your pond can be just as inexpensive. Ask your buddies for some starts to plants. If you have a pond on your property or have the permission from the owner of a pond, try getting some plants from there. Make sure you have permission! Once I even asked the local Dollar Store in Florida if I could have some plants from their pond. They said yes and I walked away with some great free plants!
The local dump is also a great place to scout for all sorts of materials. I have some huuuuge pots meant for trees that I got for free. They're expensive when you buy them. Just so you know, you're taking a risk when getting stuff second-hand--there could be yucky stuff on/in them. Make sure you wash and disinfect whatever you get.
Now that the money thing is taken care of we need to take a look at the biology of a pond.
Sediment: This is where so much of the life of your pond starts and eventually ends. You can obtain this in any manner of ways, perhaps the best being from a friend's well-established pond. It's the muck at the bottom of their pond and in their filters. Seems nasty but this is far from true. It's chock-full of beneficial bacteria that helps cycle your pond (just like an aquarium). Note than these are living creatures that require oxygen in order to survive. Make the trip from their pond to yours as fast as possible so they do not die. If they're dead they are of no use to you. Spread this muck evenly over the bottom of your previously filled non-chlorinated pond. Note that before I add this I always lay down a few inches of clean yard clay, the muck goes on top of the clay.
Just as we came from the dust of the earth, so does your pond. I cannot state this is a simpler manner, think of your pond as one large chain that you, yourself have to weld each individual link to. Do not use an inferior metal and make sure to weld it well. If even a single link breaks, it can ruin the entire chain, all your hard work.
Plants: There are three main categories you should concern yourself with:
Marginals - Irises, reeds and any plant that likes wet feet.
Surface/floating plants - plants such as Azolla and Duckweed. Plants that spend their time living on the surface of the water. They help filter/shade and clean the water they live in. A good rule of thumb when growing these plants is to allow 1/3 of the surface of the water to be fully covered with plants. This helps fight algae and helps keep the water cool and clean for your fish. The roots are especially nice for fry to hide and feed in.
Submerged - like bladderwort, Bacopa caroliniana, waterlilies and hornwort. These also work as a natural filter for your pond as well as provide food.
You really do need these three categories for a healthy and stable pond.
Algae: Algae simply put, are plants. Here is the high tech definition from Wikipedia.
Algae (sing. alga) are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many of the distinct organs found in land plants. Though the prokaryotic cyanobacteria (commonly referred to as blue-green algae) were traditionally included as "algae" in older textbooks, many modern sources regard this as outdated and restrict the term algae to eukaryotic organisms. All true algae therefore have a nucleus enclosed within a membrane and chloroplasts bound in one or more membranes. Algae constitute a paraphyletic and polyphyletic group: they do not represent a single evolutionary direction or line, but a level or grade of organization that may have developed several times in the early history of life on Earth.
Algae lack the various structures that characterize land plants, such as phyllids and rhizoids in nonvascular plants, or leaves, roots, and other organs that are found in tracheophytes. They are distinguished from protozoa in that they are photosynthetic. Many are photoautotrophic, although some groups contain members that are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some unicellular species rely entirely on external energy sources and have reduced or lost their photosynthetic apparatus.
All algae have photosynthetic machinery ultimately derived from the cyanobacteria, and so produce oxygen as a byproduct of photosynthesis, unlike other photosynthetic bacteria such as purple and green sulfur bacteria.
As you can see, some algae in your pond are beneficial. Fish eat them, aquatic insects eat them which in turn your fish like to munch... "The Food Chain". So, don't freak out if you get some algae, be happy your pond can support it. If you have too much then you obviously don't have enough plants to keep it down. Overfeeding your fish can cause an algae bloom as can over stocking your pond as can having too much light. Don't result to chemicals to control algae, in the end you're hurting the very thing you've tried so hard to create. Nature takes time, your pond will as well. It can take a year or more for it to settle and completely clear to your liking. The best defense against too much algae I've found is by adding larger plants and never overfeeding your fish. If algae doesn't have sunlight then it won't spread in a gross manner. Remember the 1/3 rule.
Use good judgment when locating your pond. You are going to want to avoid places that are prone to flooding or pesticide/fertilizer drifts. If the only place you have floods, simply build the edge of your pond up high enough it doesn't flood. I use dirt, it's free and you'll already have some laying around from where you dug your pond. Another thing to factor in is sunlight. Most of my ponds have been in full sun but a person can have one in part to deep shade as well. This will help combat the initial algae problems but waterlilies may not bloom. It's a trade off really, lol.
A pond without filters and pumps
It's simple really: your pond IS your filter. Well, it and the plants, animals, and other organisms. If you have balanced it all well enough, there will be enough plants to feed off fish waste, enough sunlight to help the plants photosynthesize turning that waste into life-giving oxygen for your fish to breathe. It all works together, remember the chain and you'll do fine.
Let's recap our lesson for the day.
You need a liner.
Get some pond sludge from a friend and HURRY home with it.
Avoid flood-prone areas.
When growing lilies you will need more sunlight than for other species.
Do not over-feed or overstock your pond.
Wait about 3 WEEKS before adding fish; this gives your pond adequate time to cycle and prepare itself for the larger bio-load.
Add fish a couple at a time and wait a week or so before adding more.
Don't forget the three types of plants you need: marginals, surface, and sbmerged.
Cover 1/3 of the water with plants.
Remember, a pond takes time. Impatience is what got the possum run over...your fish belly up.
Until we talk again,