Stage 2 - under-gravel heating

We researched under-gravel heating and found that it was essential for a planted aquarium as it:

(i) raised the temperature of the gravel around the plant roots by a few degrees which aids in their growth

(ii) the temperature difference between this layer of gravel and the water in the tank sets up a convection current which aids in the cycling of nutrients

so we looked in to prices. These varied from about $90 - $500 depending on the brand and the size and wattage. We managed to pick up a 100W Rena cal system for $20 on ebay.

Unfortunately it didn't come with suction caps and we had trouble finding the right size. In the end we used air-line suction caps that are split to allow for multi-size tubing. This was fine but would have been better to have closed suction caps.

To lay the under-gravel heating dry out the bottom on the tank completely (this allows the suction caps to actually stick rather than sliding around) and lay out the cable in a back and forward pattern.

You can use suction caps to stick the cable to the back of the tank as well.