(06-27-2016, 06:25 PM)CatCuddler57 Wrote: I had a thirty gallon fish tank. I changed the PH depending on the fish because some of them prefer a higher ph and others like lower ph. I know that with goldfish, you have to watch out for to much ammonia. I've had fish on and off for years, without luck. I'm not sure about the filter, I had the guy at the store help me pick it out. As for the guppies, they did breed fast but she never had more than eight in the tank. As for the idea that some fish aren't hardier than others, that's simply not true. In a tank with baja sharks, angelfish, and sucker fish (pleco?), angelfish always die first, then baja sharks, and then the sucker fish. Some fish have a greater degree of tolerance while some fish are downright persnickety.
You do not need to change the PH of your aquarium water. Messing with aquarium water PH is dangerous for the fish. Just let the fish adopt through accumulation when you first introduce them to your aquarium.
Ammonia should be absolutely 0ppm for all fish species.
You just proved Ram was right. Your idea of hardy fish is none other than who die the last under unfavorable conditions. Debating who usually dies the last is pointless. Why not just provide the ideal conditions so all your fish can live instead of dying one by one within short amount of time?