We recommend keeping the Clarkii Clownfish as the the only clownfish in the aquarium as they are often aggressive towards other species of clownfish.
As with most clownfish, the Clarkii Clownfish is best kept singly unless a pair is introduced together. It may nip at passive tank-mates who wander near its host anemone or territory. Generally, it is a great fish for the reef aquarium and spends much of its time nestled peacefully in its anemone. Larger specimens have larger territories and are best kept with fish of similar or larger size.
If you want to take the risk and try keeping other species of clownfish in the aquarium, it is best to do it in a larger aquarium of 200 gallons or more and provide each clownfish, or pair of clownfish, with their own anemone. Adding all of the clownfish at the same time will also help to reduce territorial disputes. While following these tips will increase the odds of success, they do not guarantee it.
The Clarkii Clownfish does not require a host anemone for survival; however it is a real treat for any hobbyist to observe the symbiotic relationship between the clownfish and its host anemone. The anemone provides a safe haven for the clownfish because its tentacles will inflict a painful sting on all but other clownfish. The clownfish, in return, chases off fish that threaten to pick at the anemone and brings it scraps of food. The Clarkii Clownfish prefers Carpet Anemones.
Maintaining Ammonia at 0 ppm, Nitrites at 0 ppm, and Nitrates below 10ppm will help to keep your Clarkii Clownfish happy and healthy. We recommend doing a water change soon after Nitrates rise above 10 ppm. Maintaining proper calcium (420-440 ppm), alkalinity (8-9.5 dkh - run it 7-8 if you are carbon dosing) , and magnesium levels (1260-1350 ppm) will help to keep pH stable in the 8.1-8.4 range. We recommend a specific gravity of 1.024-1.026 with 1.025 being ideal for fish. Temperature should remain stable as well and should stay within a 2 degree range.
Offer the Clarkii Clownfish mysis shrimp and frozen herbivore preparations 4-5 times per week. Their diet consists mostly of meaty foods, however they will accept some algae based foods as well. Soaking all fish food with vitamins will help keep your fish healthier and make them less susceptible to disease. We recommend soaking food in garlic as well when adding new fish and whenever your notice ich or other disease in the aquarium. Garlic will help repel external parasites and will boost the fishes immunity.
Remember to feed slowly. Leftover food will cause nitrates and phosphates to rise. If you see food falling to the sand bed and into the rocks, you should feed slower and give the fish a chance to eat before adding a little more. Using a turkey baster allows you to target food to different fish. For example you can feed the aggressive fish on one side of the tank and then squirt a little bit on the other side for the less aggressive fish. This way all the fish get a chance to eat enough.