My betta is in a 3-gallon tank. Does he need a heater and which one?

Bettas are tropical fish and do best in water between 78 F and 80 F. A heater is typically required to maintain stable temperature. Rapid fluctuations in temp can be stressful. You should also check the water quality and chemistry. Poor water quality can cause the symptoms described. Filtration and regular partial water changes are necessary to keep a tank clean.

A 2.5 gallon tank is fine for a Betta and 2 snails. If you have artificial plants, use ones made of silk instead of plastic which can harm delicate fins. You'll need a heater also. Bettas are tropical fish and do best between 78 F and 80 F.

Most of the compatible fish are schooling fish that do best in groups of 4-8. This would include Neon Tetras, Ember Tetras, Harlequin Rasboras or White Cloud Minnows. That many fish may be too much for a 3 gallon tank. Other non-fish option include Ghost Shrimp, Zebra Snails or African Dwarf Frogs.

The small size will limit the species of fish as well as the number. White Cloud Minnows or Guppies would do fine in a small tank. You could keep no more than 2 or 3 fish total. If you are looking for company for your Betta, the same species can be kept. Other options include Otocinclus (Otos), Corys, Platys or Harlequin Rasboras. Again, no more than one or two in addition to the Betta. Water changes for any tank are simple. Change no more than 30% total volume at a time. Use a water conditioner to remove harmful chemicals and make sure the water is temperature matched to prevent stress or shock. Rinse the filter in tank water, not tap water, to preserve beneficial bacteria. Vacuum the substrate every couple of weeks.

Bettas do best in water temperature between 78 F and 80 F. An algae eater should be okay, but it depends on your individual Betta. Some don't mind bottom dwelling tank mates. Watch for signature of aggression and remove the algae eater if necessary.

That may be normal coloring. Velvet is an infection caused by a parasite that can give a golden or shimmery appearance, but it is an uncomfortable infection. Your fish would be flashing about and rubbing against anything in the tank. If Kenny is behaving normally, it could be that he is an extremely handsome specimen. :-) Bettas do best in water that is between 78 and 80 F. A heater is not necessary if the water is in that range. Use a heater to prevent drops below 74 F which can lead to stress and illness.

Mushu is very cute! Betta care is very easy. Ideally, a 5 gallon tank should be used to house your Betta. A smaller tank can be used, but the maintenance (water changes) will be much more frequent. A filter is always recommended otherwise water changes will be required every few days to maintain water quality. With a filter, 20% water changes can be done weekly or every two weeks. Use only aged or conditioned water that is temperature matched to prevent stress or shock. Choices for conditioners include AmQuel Plus, NovAqua, StressCoat, Prime or StressZyme. A small submersible heater is necessary since Bettas are tropical fish. They do best in slow moving water between 78F and 80F. You can feed a pelleted diet such as Hikari Micro Pellets until he grows bigger. Baby brine shrimp, daphnia, bloodworms and blackworms can also be fed. Feed one or twice daily. He should only need 2-3 pellets at each feeding. The conditioners and food can be found in the aquarium section of the local Petco. Please request a consultation to discuss care in greater depth or post another question in the Forum if necessary.