tds ph kh carbonate bicarbonate buffer alkalinity

Have had my gulper almost 4 weeks and I think he finally ate his first meal last night. Anyone know what they act like after they've eaten? It was just a gourami so not big, but he seems stressed and the only thing other than eating must be pH which I've managed to keep at 7 even though my...

@RD. @jaws7777 @Drstrangelove @Angelphish @Just Toby @kno4te @philipraposo1982 @duanes Some people believe performing large water changes can hurt or even kill their fish. I've even seen threads where it's also been suggested that large water changes can harm or kill the...