Unlike in the case of a new aquarium setup, with an existing set up, making use of the existing microorganisms within the filter and substrate is the most efficient method and poses the minimal risk of failure. Yet, there are some notes on transplanting of beneficial microorganisms that are worth knowing: firstly, it is ideal to remove the filter before demolishing the existing aquarium and if possible, let it run in the other aquarium in good condition until it is installed in the new tank.

The aquarium water becomes cloudy when aquatic plants are removed or the composition materials such as driftwood and stones are taken out of the tank. The filter should be removed before proceeding with these removal works to prevent the cloudy water from going into the filter. In the event that there is no appropriate tank available for keeping the removed filter in, the water inside the filter must be completely drained after the filter is removed from the old aquarium. Aquarium makeovers usually take time. During this period, the filter should be kept empty to expose the filter media to the air so that the microorganisms within the filter can get oxygen.

Secondly, the Aqua Soil used for the existing substrate should basically be replaced with new ones since the old substrate may be covered by a significant amount of sludge or it may be in an excessively anaerobic condition which can lead to deteriorated water quality or algal growth.

An important point for the removal of the existing substrate is to avoid removing completely the brown muddy water left on the bottom of the tank. Since this brown water contains abundant live microorganisms, it is advised to leave this water to the extent that the bottom of the tank is barely covered with it.

Spreading substrate additives or Aqua Soil on top of this brown water allows the new substrate to have rich beneficial bacteria which have grown from the microorganisms contained in the brown water. Meanwhile, ensuring a good balance between aerobic and anaerobic bacteria is very important for the substrate.