The dimension of this system is 900 x 900 mm x 300 mm and the fish tank is a 300 liter capacity loft tank that is readily available in the market.
The wooden framework was developed keeping in mind the outdoor conditions and was treated with a PU coat (weather proof sealant).
Once the framework was assembled, the inside was lined with a pond liner.
The growmedia for this system was in two layers .. the lower half was filled with 25mm gravel and the remaining top half was filled with LECA.
For this system i started cycling with fish.
the formula i was following in the past was the same i used here. So what i did was once the system was fully plumbed and the water filled in the fishtank, i ran the system for three days without fish.
Then on the 4th day i added 5 goldfish, and did a water test. After the first week i added another 5 fish and every week gradually i started adding more fish.
The first few weeks you will notice the PH reducing and the ammonia level slowly building up .. once you see the ammonia building up .. its time to add some seeds so that there will be takers for the nitrate when the bacteria start converting the ammonia into nitrite and then nitrate.
Here are the results from the testing that was done in 8 weeks.
you can see the progress gradually.