It is kind of old. My other betta is pushing past 5 years now. I know where the parameters should be, I just didn’t have time to test the water yet. I also did not have time to do a water change either. It’s definitely some sort of parasite or infection going on I want to believe. I will be able to test the water and do a water change when I get back home from work. He’s a smaller betta, a koi plakat. For all i know, he could possibly pass away while I’m at work. He was looking still very rough this morning. It wouldn’t deteriorate fast water quality wise. He had a strong bio cycle. I modified the filter to make sure of that. I’m a pretty advanced keeper, I’m just stumped on what to do with him treatment wise.
I was with goldfishkeepers.com too. Welcome here. I would remove the minnows. 2 goldfish in a 40 breeder will grow to their potential nicely. Just keep testing the water, feed very sparingly until you know your tank is cycled. Do weekly water changes and use prime as your conditioner too.
2.5 years is kind of an a old betta. Those temps are too low for a betta. They at least 80 degrees water temps. I would do a complete water change. Nitrates need to be under 30 ppm for goldfish probably more with a betta. Your tank is very tiny and things can deteriorate very fast in such a small setting
Ammonia: old 0ppm new 0.25 just before water change
nitrate: old 10-30 ppm new 20-40 ppm--What type of test are using test strips or liquid form?-- Ammonia should always be zero and nitrates should always be under 30 ppm. What are your ph and nitrite levels
Keeping large iridescent sharks and a turtle is not a good idea with fantails. They cannot compete with the aggressiveness of those two. The turtle will eventually view the goldfish as a food source.
I see that you are feeding flakes. This is a horrible food source for goldfish. Invest in a good gel food.