Here, I am going to share how we built a custom concrete pond that will last forever, protect the fish through the harshest of winters, provide easy maintenance and beautify your home.
We expanded our living space outside and are able to enjoy the pond year round. The pond provides extra seating in the small courtyard, visual interest and soothing sounds of running water. While sitting on the ledge you are able to sit and look into the pond and entertain your guests.
This project took a few weeks to complete. As you can tell in the photos there were many other projects going on in the construction of our new yard. In order to complete this project, moderate construction skills and knowledge are required but by no means do you have to be an 'expert'. The most difficult aspect is having access to the concrete forms and knowing how to properly set them up.
This instructable can be taken and applied directly, or the ideas and methods can be used to influence a variation of this design/process of your own. Good luck and enjoy!
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Signing UpStep 1: Koi pond information
I just want to touch on some of the basics of koi and building a pond. I did a lot of research before designing and building our pond. I have found there are many myths out there about koi and want to dispel a few of them here. Koi are beautiful fish (in the carp family) that can live for many years if properly cared for. The better the environment you build for them the longer they will live. As you will discover water quality is key in keeping koi healthy.
Myth 1. Koi are expensive.'
It is true there are koi fish that go for thousands of dollars. Most cost 20 bucks or so and on up. You don't really need many fish, as we found out they BREED like crazy. So only buy a few to start. I recommend buying from a koi farm and not just any pet or garden supply store. You will get better quality fish in health and they are often cheaper at a breeder. By speaking to the breeder we gained a lot more knowledge of koi and learned about all the different types and colorings.
Myth 2. Koi ponds need to be large.
'''A general rule of thumb is one inch of fish per 10 gallons of water.'''
You can make a pond any size but you do have to be careful of over crowding in smaller ponds. I often heard people say koi only grow to a certain size based on how large your pond is. This is false. as long as you have healthy water quality and feed them they will grow to any size. The more you feed them the more they will grow, these fish eat nonstop. But with this in mind you have to determine what is right for you and your pond, such as how many fish you would like to have. Over estimate because of breeding and you will probably want more than you plan on.
Typically A koi pond should be no less than 1000 gallons (ours is around 2000 gallons). Ideally, you want to change the water twice a year (spring and fall). We aim for fall since the water will be good quality for the winter, therefore, putting less stress on the fish during the cold months. You will see further in this project how we installed a valve in the bottom of the pond to provide easy clean out, making maintenance fairly painless. There are a ton of water treatment options, filtering and pumping systems one can buy. As you get more involved in the hobby of koi ponds you can decide what is best for you. We started very simple expecting to add more later, though so far we haven't needed to. The pond stays crystal clear with the simple filtration system we started with, which is explained later. It is important to note that even though your water may be clear, it does not mean the quality of water is healthy for your fish. The 4 main water quality tests you should do regularly (especially before putting fish in your pond and again a day or two after the fish are in the pond) are PH, KH, Ammonia and Nitrite.



















































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http://en.wikipedia.org/wiki/Water_hyacinth
But I think you meant that you used a 1,500 gallon per HOUR water pump. 1,500 gal/min would typically require a 10" pipe. I think a 1,500 gallon per minute pump would turn that 2,000 gallon pond into a whirlpool!
I think your fountian concept is great because it will oxygenate the water and it a very pleasing feature in the pond. I like the high wall around the pond. it gives it character and prevents the fish from jumping out. The overflow is a good idea, but I would put a netting accross it, because the fish do jump out. Better safe than sorry.
Where did you hide your filtration? In my pond design considerations, aesthetically hiding a large filtration unit ranks high on the priority list. The larger the filter, the less maintenace is required. The filter also needs to be located in an easy to access/clean location. The filtering options you select will litteraly determine how much time you will need to spend maintaining, so I'm very curious what you have selected for that.
In terms of water quality, I also monitor nitrates (N03), they are not as toxic as NH3 or NO2, but they do tend to accumulate to stressfull levels for the fish. In addition, NO3 is a fertilizer and that is what leads to algae problems. In the cycle of the fish poop, it satrts as toxic NH3 which gets processed in toxic N02 by one typeof bacteria, then the N02 gets processed to the less toxic N03 by a second type of bacteria. Both these type of bacteria require oxygenated water to operate. The N03 accumulates at the end of the cycle and there are 3 (4) ways to deal with it:
1- plants use it as fertilizer, so put fast growing plants that have their roots in the water (can be in a pot). when they grow, they absorb/export the N03.
2 - partial water change 10% every week or 2 to slow the accumulation of N03. This would be more effective in maintaining water quality than 2 complete water changes/year. When you do a complete waterchange, you also eliminate all the useful bacteria that keeps you eco-cycle going. It takes weeks/months to re-establish it. This would be when the toxic NH3 and NO2 will spike until the tank is cycled and the bacteria equilibrium is re-established.
3- there is a 3rd type of bacteria that absobs the N03 and that just releases harmless N2 (nitrogen = 79% of what's in the air). But the challenge is that this type of bacteria needs a low oxygen environment. So a traditional filter with high oxygenated water flow does not work well. In nature, this type of bacteria lives deeper in the substrate at the bottom of the pond where there is little oxygen. You can recreate this in a pond or an aquarium by having a deep sand bed.
(4)- If all of the above is not done and there is a bit of sun, this is where the ugly algae bloom comes in to consume the N03. It's nature's way of dealing with it to re-establish a healthy balance.
So in all my experience, I learned that there is no need to fight mother nature with chemicals. Once I understood the eco-cycle that I was trying to replicate at home, I could make sure that all the parts of the cycle where fulfilled and then enjoyed very healthy, low maintenance aquariums/pond.
It would be great if after a year or two, you updated your instructables with what you would have done differently (if anything) with the hindsight of experience.
Again, great job, I am really impressed with the concrete work!!
You can also use barley straw to lower or is it raise? can't recall off hand the water pH which provides a less attractive environment for the algae to grow in.
Snails and plants can help too.
The main goal with any ecosystem is BALANCE - too much of anything creates imbalance and lots of extra work!
BTW the fish also consume the algae and it is the green feed that gives them their brilliant colour! Fish enthusiasts often pay $100's more for fish grown in algae ponds so green its hard to see the fish!
Please plan ahead how the fish will be kept over the winter if you are in a northern climate. Fish are just as intelligent as cats or dogs and some become quite attached to their people! All that is required is to keep them from freezing - I use a 90 gallon tank out in the unheated garage with a styrofoam top, sides and an air filter or bubbler. The fishes metabolism slows right down to semi hibernation states so they only need be fed about every 10 days, water plants and lily bulbs will keep nicely in the tank too.
I even have lovely ceramic pots the big ones that I sealed the hole in the bottom with silicone and grow a water lily in and stock with a couple of little gold fish!
My fountain has a couple of little guys too because I don't leave it running 24/7 and those darned mosquito's are real opportunists!
So you don't have to go Big to have a nice water feature in your garden - even a betta is happy in gallon of water or the white clouds and tetra's do fine over a summer too outside.
http://www.backyardaquaponics.com/
Anyhow, about the Koi. You said they will breed like crazy, and yes, they will but they will also spend a lot of time eating the eggs and (ew) their own young, so if you want to keep them babies you can pull plants after spawn with all the sticky eggs on em and put them in a large tank and let them grow from there. There's plenty of info on teh interwebz about goldfish breeding.
Also, those 30 cent comets that they sell int he feeder fish department at gold fish stores will get as big and as beautiful as koi, only for a LOT cheaper and will also cross breed with the Koi (all types of gold fish are generally the same species) giving you fun different varieties!
Have fun! I know this started as a hardscape project but you may soon find yourself more the fish hobbyist (it's happened to soo many, myself included!)