The activated carbon is held in a DIY column that hangs on the inside of the sump. Water is fed to the column using a dedicated Hagen Aquaclear 402 pump, which is located on the upstream side of the last sump baffle. Water after passing through the activated carbon is then returned on the otherside of the baffle, where the return sump inlet is located. This eliminates the chance of any water being processed more than once before returning to the display tank.

2 litre activated carbon column hanging on the inside of the sump.

Hagen 402 pump feeding water to the activated carbon column.

The column holding the activated carbon was initially built to be the the first stage of an altered Tap Water Purifier (deionisation column from Aquarium Pharmaceuticals) set up for producing deionised water for evaporation top up. A new deionisation column was constructed and it was subsequently installed to process the aquarium water. The column holds approximately 2 litres of activated carbon that is replaced at the start of each month.

The activated carbon being currently used is from Sigma Chemicals in Perth. The Marine Aquarium Society of Victoria put together a joint order between a number of members to reduce the freight expense. The cost worked out to be around $7 per kilogram delivered. That price will vary depending on the location it is delivered to, amount ordered and if they change the price of course.