FO Outdoor Saltwater Pond 5.000 lt


New member
Hi all,

I want to share my outdoor salt water pond, this is a 5.000 lt pond, actually not too big for koi. I started this simple project on 8 nov 2020, and i will updating this thread regulary, either this will fail or success.

The idea why i tried to makes a saltwater pond is because one day, i walking along the sea side and jetty, i saw many rabbitfish and brown surgeon eating the algae in the barrier wall or the jetty. This make me think that converting my pond will be an interesting idea. So, i start to sell all my freshwater fish and start this project.

And since fish can tolerate salinity on much bigger value than invertebrate. So, i think the idea arent impossible. And i read from some literature that saltwater fish can tolerate even up to 20 ppt or even lower, eventhough to keep on 35 ppt is better, but many fish store are keep lower than 30 ppt, than i get the middle line of 25 ppt for my pond.

And since i want to run this project with minimum cost, so :
1. i use a DIY salt, using the formula that i found from google.
2. using filter media that comes from koi setup.
3. DIY injector skimmer cap only for 1.000 lt, will upgrade it once i have spare money.
4. UV sterilizer total of 63 watt for killing the green algae.
5. 2 return pump rated 9.500 each, 1 for return and the other 1 are divide 2 channel, 1 for supply UV and second return again to pond as bottom wave maker.
6. wave maker rated about 8.000 lt

The pond is very simple in rockwork
1. using DR only. And still rearangging once i got the idea, because i still not feel satisfy with the rock work.
2. bare bottom, because i think if i put sandy or crush rock, it will collect a lot of waste, and makes cleaning very difficult.
3. start to by putting though and hardy fish, but later i put more delicate fish because i think and i see that the environment are support for the fish

As for DIY salt, there are several tips to mix to makes a saltwater salt, and since im not an expert in chemical, so i just copy it. And since some chemical are not easy to find, and some are so expensive, so i just mix 7 major element and it is easy to find :
1. NaCL
2. Baking soda
3. CaCl2
4. Epsom salt
5. MgCl2 (not yet using this chemical)
6. Potassium Cloride
7. Amonium Cloride
The amount of each ingredient are written in the literature

This is and outdoor pond, so i tried to let it be hit by heavy rain and check the salinity, it lower by 2 degree, ex from 25 down to 23, and if it hit again by heavy rain it will drop again by 2 point. The fish i saw is no effect, and still eating normally. So, in the early after setup, each after rain, i top up with DIY salt to hit 25 ppt again. After i experience that heavy rain is no problem, but i will lose a lot of money to make a DIY salt. Then i counter that with knock down roof top above the pond just counter the rain during rainy season. And here is the pic and the video that i attach.

Here is the video


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New member
Very Nice - Thanks for sharing. I love unique takes on the typical saltwater/marine setup. Maybe get a top view looking down video for us (from above the water surface. I know salt water fishes are best viewed from the side, but I like would like to see a top down view. I have a shallow indoor 4'x4'x1' FOWLR lagoon that I love the top down view of! I don't have the power heads pointing at the surface so the surface is calm to look downwards on and see the fishes swimming in and out of the rocks and also greeting me.


New member
Hi jhentr, actually i want to shot from above, but the water reflection makes the photos or video cant be seen. Im also likes to see the fish from above, its kind like see from jetty. And when feeding the fish, its also a pleasure, seeing fish grabbing food from my hand.


New member
Here is the update of my outdoor saltwater pond. Some of the fishes are taken out, fews are put in my friend tank, the platax, annularis, snapper, damsel, green scat, are sold. The reason to taken out some fishes are to give a roo,m to other fish that i want to keep. For the annularis, i sold it because i want to keep adult gorgeous koran angelfish.


New member
Awesome! Can you do a video on your filtration?

Hi, this is my video about filtration.

It is 3 block of filtration, actually this is made for koi filtration, since this is a koi pond previously. The 1st chamber is chamber that collect heavy dirt and poop, chamber 2 is for filtering small particle and debris, since this is outdoor pond, so it collect also dust from the enviroment, and chamber 3 there is 2 pump, 1st is for return pump and the 2nd pump is for feeder to UV + split as a return pump also. Cleaning the japmat and sponge filter is usually each every 2 weeks.


New member


Wow very cool, love your fish selection. Really love the adult batfish, super cool! How big of a heater do you need? Do you live in a tropical country?