Need some betta advise/reassurement
All right, so excuse my longer post... Ok, so I have had my 5gal up and running for 2 months now, fully cycled 0/0/5-10ppm (as per this afternoon) with my resident Otocinclus who by the way is one cool dude :)
My issue is this: I have gone through 2 bettas in the last 2 months. They both caught what looked like body fungus on day 2 and died within 72 hours of purchase. I have the freshwater API kit and test regularly so I did water changes as needed so I doubt the water quality was the issue. I decided no more petstore bettas (I tried 2 different stores) and am ordering a HMPK from a breeder. He should be here next week as he will be 12 wks old and able to ship. However, I have fears that this more expensive fish will have the same fate as the last two... despite the cost I will be more upset if he dies... and I feel like I am a terrible fishkeeper...
So.. any advise on how to avoid this for my new fishy? I feel like I did everything I could... and yet.. Also, any different care for the young 12 week old fish? I heard you are supposed to do daily or every other day 50% changes due to a hormone they secrete, anything else I should know? I really want this to go perfectly so any and every knowledge ya'll can send my way please do so!