What is one of your secrets to keeping fish all these years and what kind of fish do you keep if you don't mind saying, thanks?

Never feel tempted to feed your fish more than what they can actually eat, the less the better I learned. Two small feedings a day is even better than one big feeding, that's if you have time. Always quarantine any new fish before adding it to your main tank. Learned this the hard way. A hospital/quarantine tank is a must for any serious fish keeper. You can never over-filter but most people often under-filter. My number one secret in the fish hobby is that using hydrogen peroxide is extremely effective against blue-green bacteria also known as Cyanobacteria. I had an outbreak of the stuff and no matter how many water changes I did or how much of the stuff I vacuumed, the next morning it spreads like rabbits breeding like there's no tomorrow. Poured in four tbsp of hydrogen peroxide into the tank and voila! The so-called blue-green algae completely disappeared! Out of sight and gone! I keep wild-caught altum angelfish, Discus and African Cyphotilapia gibberosa blue Zaire each in their own specie tank and each tank at 125 gallon. Thanks in advance for participating. Best secret will be awarded with best answer. :)