As mentioned I want to use ceramic rings in the middle section of the filter. I do want to change/wash them every once in a while so easy removal is key. I used a new (mind the detergents in used ones) bag that we normally use to wash delicate laundry. I put in in the filter and slowly filled up the bag with rings. I cut off the remaining piece of the bag, as it was too large to fit in the filter completely. The result:
I wanted to have a black backside in the aquarium. I purchased black foil and specialized glue at the pet store. See the result below, which I'm quite fond off.
With two 90 degree corner pieces and some standard tubing (that I knew would fit the pump!) I created the tubing upward out of the innermost filterchamber and via a 90 degree turn to a horizontal piece. The last 90 degree turn then guides the water to the outflow. I created the outflow from a piece of PVC that I had lying around. I shopped the internet beforehand, but only found expensive outflows for either original filters or lily pipes. The latter is nicer, but expensive. I simply cut the pipe, poured hot water over it, bend it in a 110 degree corner and flattened it. I then attached it to the tubing. The end result:
Note that I bent two small pieces of plastic to form attachment clips of the filter to the tank. Easy does it!
I then filled up the tank with soil in order for the filter to remain in place and water. I tested the filter and checked it regularly. As you become used to it not leaking or malfunctioning, you automatically check less frequently. I checked water quality using a 7-test strip and kept this running for about two weeks.
Next up will be planting the tank.