Have anyone ever thought about this??

My dad wants me to build a pond for him in a lot of land he just bought recently. It is going to be fairly big (Im not sure the size yet) but instead of keeping goldfish/koi like people used to do. Im thinking about going with cardinal tetras, angels, rams, discus, some corydas catfish, maybe a shoal of sam algae eater too. And lots of ghost shrimps as they are very cheap anyway.

Water quality in the area is again soft but neutral (low hardness but pH and 7). Which is also been great for keeping tropical fish in my experience so far. Temperature in the area would never make the water go below 25C. Highest temp would be 30C but for a large body of water like a pond, I'd say 28C would be the lowest.

I plan to use a variety of plants to keep the water clear as it is very important to view tropical fish.


Do you think this idea would be possible? Any suggestion is really great.

Im still deciding which filter should I take, I have done some research and it is said that gravity fed filter would be best for big ponds. But since Im having small fish and plants there, would be possible?

Also with gravity fed filter, the water outlet will be at the bottom of the tank, which means I can not use substrate such as sand?
I thought about having a small area of the tank that is completely empty that is netted to create small chamber. That area will be the only water outlet for the whole pond.

Also for tropical fish, would 50-60cm deep is enough? Should I try to go 100cm deep? Im afraid that I won't see bottom dweller fish if I do that

I presume this will be in Vietnam?

Filtration:

The "problem" with any outdoor pond is not just the fish waste but everything else that can and will get blown in, leaves general dirt etc.

In the main there are two types of filtration systems. Pump fed or gravity fed.

Gravity fed
Gravity fed are usually best because you can make the pond floor slope to a central point and install a bottom drain. Which in turn feeds a vortex chamber. However here in lies the problem. In order for a bottom drain to work well it sucks in water and dirt, in order to do this it needs an opening of around 2cm at least, but as you want cardinal tetras they are small enough to get sucked in and..... you can't put a mesh on the inlet as that will stop the dirt from being sucked in, or if you tried a mesh it, it will soon clog.

Pump fed
That leaves you with the option of pump fed filter, a filter pump has large holes in order to be able to remove any large waste, but will still have the same problem with regard to sucking in small fish.

Gravel
Or you could go with an under gravel filter, like fish tanks use, there is one available for ponds called the spider filter. But like a fish tank under gravel filter, you will have to empty the pond and clean all the gravel on an as and when basis which is not an easy task (trust me) Also an under gravel filter can not remove large things such as leaves etc.

Plant filters

I have yet to see a "this will work" idea for a pond that involves a balance between fish water and plants, and of course the more plants you have the more waste you create as and when they die (Usually when you are not looking) so you will need external filtration.

Water depth
The water depth of 60cm will be fine if the pond is in Vietnam, it only has to be deeper to stop it from freezing. Which does happen here in the UK.

Construction
Although the depth will only be 2 feet, you would save yourself a lot of future trouble if you build the pond from concrete (Unless its really really huge, lake size) the reason is simple. Being made from concrete it will never move or collapse (if its done right) where as a pond attracts a lot of visitors and the edges may become unstable and give way. It is possible to not use concrete if the pond is big and you have room for gently sloping sides, but it is down to size of the pond.

Finally
What ever you choose to do, take pictures as you go and post them here. I wish you good luck.

Just to add, if you do intend to put Discus or Angels in there I would make it 60cm deep rather than 50 which would be too shallow when they're adults.

Thanks for replies guys. Those were really helpful.

I have looked into both concrete and liner and decided to go with concrete. That also mean it will take a month at least before I can have fish.
I am also worry about tree roots. Since the whole theme is amazon river, leaf litter would make great addition and only hard-wood tree would work. And these tree can grow and penetrate concrete.
I won't have a big pond that have slope and no concrete. Simply because then big fish would never go to the shore.

I have decided that the pond will be at least 60cm deep with some area shallower.


For filtration, how about I have a surface area about 20x20cm that is netted to prevent small fish to get sucked in? And maybe have 2 of them? Would the flow be too strong that it will suck the fish in anyway? If there is no slope then it would not be capable of cleaning the waste right?

What if the pond shape is not circular or square but more like a river setting? Where should the drain be placed?

Also I prefer the idea of gravity fed over pump fed.

I will have have lots of plants anyway to keep the algae at bay.

I have been going to fish shops very often to see what is available. They have external filters for ponds too. Would them be useful?
Also right now Im considering clown loaches and plecs. They seem to be a perfect fit for such setting. Discus will have to wait since they are too sensitive.


The whole project is right now in the planning phase. Right after my semester end, I will start writing, maybe a blog, about this :D

Oh and just to add. I dont have ducks but I do have 2 geese..... from my understanding, they are vegetarian. But should I be worried?? Apart from the waste, do they eat my fish?

I can easily build something to prevent them to get to the pond anyway. They are like dogs to keep people away from the house so I don't want to cage them

Update on the project.

I have been to the site and decided that the pond size will be 5m long (maybe I will go 4 or 4,5)x 1,7m wide and the dept will be vary from 40cm-80cm. (I have to make sure it is safe for kids).

The idea is I will have the water shallowest at the point at the water input (like a stream) then it gets deeper toward the end of the pond. At the end there will be a water drainage that drain the water into the filter chamber. Hopefully all the fish waste will be push here with the current.

My Question:
with such size, how big should the filter chamber be? And how strong should the water pump be?
The plan is there will be an aviary over the pond so maybe filtration will have to be good. That is also why Im thinking about reducing the length to 4m

Safe for kids?
Sorry to say this but it is possible to drown in 2cm of water, so 40cm is NOT safe for kids.

An aviary above or even near the pond is asking for trouble. All bird poop and old feathers etc will either fall or get blown into the pond and soon contaminate the water, you would need a filter bigger than the pond to cope with it.

I would suggest you install a bottom drain (or two) as that will be the only chance you will have of keeping a pond that size clear. I would suggest you run them into a vortex chamber to make life easier.

The pump size depends on two things. How often you want to turn the water over, and pond volume.

You calculate the pond volume, then divide it by the number of hours to turn the water over. Koi pond owners usually turn the water over once every 2 hours. 4 should be ok for you, depending on stocking level. Then you find a pump that can pump that amount of water ever hour, but don't forget to allow for pipe friction loss and head height. (Often the easiest thing to do is get the next size of pump up from the one you figure)

The filter size again is determined by the pond volume and turn over rate. It has to be big enough to cope with both. The bigger it is, the better it will be and the less cleaning it will require.

As for you question about will geese eat fish the answer is they may do. They will not always seek the fish (some do) but they will have no problem swallowing a small fish when feeding / drinking.

I will work on the volume then post it on here.

For the aviary, I am well aware of birds poop and feather. That's why I am asking for filtration advice. Too much filtration also means more flow and that is bad for some fish too.

Im going to have lots of plants with low level of stock. Im planning having some big trees too and I am thinking about Sonneratia pagatpa. Even if I can deal with ammonia, there is still nitrate left to deal with which trees and plants would be great help.

Well, that's the idea anyway. I can always seperate the aviary if it doesnt work and I have decided to keep the geese away already. They're true vegetation destroyer

Update

I have done some planning and draw some basic designs and gave the designs to my friend who is studying engineering.

I have estimated that my pond volume would be around 3200-3800 litre. So I guess a pump would have to be able to pump 2000litre/hour? Additionally, how big should the filtering chamber be?

I will post the design soon so you guys can give opinions.

Right now Im thinking about 4m long. Dept is divided into 3 sections. 40cm deep (The first 1,5m of the pond), 50cm deep (The next 1m of the pond), and 80cm deep (The last 1,5m). At the deepest section, I will create a slope to the middle and place a drainage there.

For section 1 and 2, at the point where it moves to the deeper area, there will be a 3cm wall so I can fill those area with sand or substrate then I will plants some plants there. Since there is a slope at the deepest area, Im still thinking how should I do the planting there.

Worries
Filter location: If I put the filter at the end of the pond, it will save money on pipe and will takes less effort as I do not have I dig all the way back to section 1 to install the pipes.
However, if I do this, would a pump 2000l/hour be strong enough to pump water through 4m of pipe?

If you install a bottom drain in the middle of the pond and either side slopes towards it the pump will be sitting in a vortex chamber at the other end of the bottom drain pipe (not the pond end) so it never have to pump water up a pipe.

You also need to consider how the water will return to the pond. Since it will be coming down a pipe, you could make a waterfall or.........