We have had our half moon betta for 6 weeks now. He was in a 20 gallon tank, cycled, no other tank mates, filter and heated to 78-80 degrees, but no salt added. We have been feeding him bio-gold pellets, fasting 1 day a week, giving a pea another day per week.
We noticed his fins we raggedy 2 days ago and then missing a large chunk yesterday. We have alot of fake plastic plants. I am assuming they were ripped by the plants as I have not seem him bite his own fins ever. I opened the filter last night and sure enough his missing chunk of fin was in there and fell into the tank...it was promptly eaten by our betta! Right now I have him in a 2.5 gallon hospital tank with aquarium salt added and no other ornaments or substrate. He seems completely fine, color is good, eating well and very active.
The problem is we do not have a heater for this small of tank and was wondering if I should just remove the plastic plants and ornaments from the 20 gallon tank, do a 25% water change, add the required salt and let him loose. Last night the 2.5 gallon tank he is in dropped 10 degrees overnight. Other option would be to leave him in there doing daily water changed and try a 7.5 watt heater. Hoping to get some advice...this is our first betta and first fish in many, many years.
If the large tank is a good idea how often should I do the water changes...we have been doing 25% per week? If the small tank seems the better idea how long should we keep him in there...his fins are badly damaged so it seems like it would take a few months for them to grow back to me.