@Chasingsunsets i gladly explain how i did it.
Though you may not need such a big container. Years ago i got it from a farmer for $50. It used to have pesticides in it so i cleaned to very thoroughly and bred trout in it.
However though successful at first, i become unwell, become psychotic, and all the trout died for i was too sick to look after them. (i cried bitter tears finding them all belly up, when i got back on my feet again) And so the container stood empty for years. Until my filter idea came up
So i bought some lengths of 6 meter long PVC corner molds from Bunnings, and build a frame about 300mm high, on the floor of the container, with 6 legs made of the same mold. Just drilling screws into the plastic molds to fasten it.
Then i drill a hole in the container where i want the clean water to come out to bring back to the pond, with a special fitting from the irrigation shop.
Then i bought i sheet of sturdy plastic fencing with large diamond shaped holes in it, that i cut to fit tightly in the container and screwed to the top of the PVC frame.(with the clean water outlet underneath i but still at least 200mmm above the floor of the container.)
On top of that i fasten two large fine fish tank filter mat i got from Ebay, which filled the whole platform on the bottom tightly against the container.
On top of this filter mat, i first fasten another part of the sturdy plastic fencing, so the filter mat was tightly packed between two of them and then i fasten 4 powerful water nozzles pointing upwards attached through a special 25mm fitting that i got from the irrigation shop and i connect to my bore pump for when i want to clean the filter under full water pressure.
Then i bought a cheap but strong nylon fish net in a perfect box shape, just a little bigger than my container when placed on the mat on the bottom of my container, measures about 300 mm higher than my container is at the top.
Then i bought 2x 200 litres of beans for bean bags, you can get them cheap from Target. And this was the biggest and hardest job, put them all inside of the fishing net. These beans are so light they go everywhere, so the only way to do it is to open the plastic with the beans in it, inside the fish net, for otherwise, i found out the hard way, they go EVERYWHERE!
After that i tied the top of the net together using a special rope clamp to tighten the net together to absolutely max tightness, and then zippy tie the netting up with long 1/2 meter long strong zippy ties. After which i cut of most of the excess above that away and used a torch burner to melt the rest of nylon netting closed, so no beans can EVER escape when i clean it under pressure.
This i place on top of the mat with the tight part of the fishing net facing down. After i that i made a wooden frame that keeps the beans loosely in place, yet with maximum space for the water to come through, and i place that on top of the fishing net with the beans in it. Fasting it very firmly, so it cannot move even under much pump pressure.
S now when the filter runs full, 99 percent of the dirt in the water is taken out by the beans, which are under pressure pushed together, for the water is about 400 mm higher than the top of beans.
In the top part of the container right above the beans i place an ultra violet light.
The water comes in the filter only during the day. For the waterfall, feeding the filter part of its stream, only runs during daylight hours. About 12 hours in Summer and only 6 hours in Winter. For the filter works so well we can easily do that now. i run an aerator during the other parts of the day. Which is 10 times cheaper to run than our waterfall pump.
i use an automatic ball valve for the pond to stop the filter running empty when the waterfall stops running. i got it from from Peter Graham’s, a farmer's supplier, to which i have attached a fake duck, instead of the orange ball, so it looks good and as part of the pond, and is no eye sore like that original ball was.
i hope that made some sense. If you would like images of the parts i bought, or a more detailed account, let me know, and i will google the images for you, and do my best to explain.
Truly it is easy as. However i suggest you do a smaller filter, than ours, for it is too big for a pond about 1700-1800 litres in size, half its size would have still been good enough i reckon, as long as most of it height is maintained, and you use beans for bean bags, that is very important.
Not sure what size pond you are talking?