I've had my betta (Kai) for only 4 days. After the first 2 days, he has seemed to go downhill. His top fin is completely clamped and the tip of the bottom fin is clamped. He mostly sits on the bottom, coming up for air. He does eat his food (pellets, one in morning, one at night).
My husband suggests that he is probably just stressed and I should just wait it out and not make any changes. I did a 10% water change today (first water change at all since I got the fish).
5 gallon tank
filtered, (cycled), heated (76-78F)
ammonia, nitrate, nitrite, 0
feeding betta pellets (one morning, one night)
using chlorine/chloramine remover
tank water 78 (it seems to drop a few degrees overnight as our house gets cold, down to 60, and the heater says it only increases water T by maximum 15F)
tank has gravel, fake plants, hidey cave
He does seem to have one white spot on one gill. Could he have ick?
He opens his mouth a lot, like a big yawn. (not sure if this is relevant)
If I increase the temp of the tank, worried that this might increase the amount of temp fluctuation between night and day.
This filter has been in there for 2 months as is past being changed. If I take it out, would this remove the "good" bacteria in the tank? Or could an old filter be the cause of the problem?
I have read about adding salt. If this is suggested, can I use "all natural sea salt"? It has no iodine in it.
btw - I had one betta before 2 months ago and it died about 5 days after I put it in this same tank.
Overall, wondering if is could just be stress and I should wait it out a few days before trying anything. And then, if no improvement, or if he continues to go downhill, then what should I try? Also, I understand that increasing the water temp is good, but what if this causes overnight water temp fluctuations?