First I drew out the acrylic parts on the acrylic. It has got protective foil attached. Leave it on there and you can use it to draw your lines with a normal pen. I then attached painting-tape to prevent the glass from breaking while cutting/sawing it in shape. I decided to go for the latter with an old, small-toothed saw. This is what it looks like:
The pictures above show the upstanding sides of the filter. I also created two squares to form the base. The two are to be glued on top of each other to form a solid base. The lower plate is slightly smaller, to allow for the silicone glue in the sides of the tank to stay intact.
I then used sanding paper to make the edges nice and even. I also created the overflows in the smallest of the upstanding parts. Note that you need to cut out the overflows quite deep, as otherwise the waterlevel will need to be fairly high for the filter to start working!!! (one of my pitfalls...)
I removed the protective foil and used a 'creme-brulee torch' we had lying around, the edge of an old table and a piece of spare wood to bend the sides in a 90 degree angle (along the table, flattened with the wood as the plastic becomes hot). The end result, already in combination with the base and the pump (for illustration purposes) is shown on the right:
As mentioned I used special purpose silicone kit to glue the sides and the bases together. This is a slow process and an ugly result - unless you're really good with this stuff. For future attempts I would prefer to spend a little more and buy 'welding-liquids'. These melt the plastic locally and 'weld' it together. The result is much cleaner and stronger.
I then cut the old cable guides to fit and glued them on the sides to hold the mat. I also used a spare piece of plastic to bend in form of the mat that is intended to keep the soil away from the filtermat for easier cleaning/removing. I then cut the mat in shape (calculations make this easy) and inserted it into the cable guides. A last photo before testing is shown in the pictures below:
The final test is to put the filter into the tank. Luckily I had done my calculations correctly and the filter exactly matches the tank. See the picture below.
The next post will cover the tubing, installation and testing