Beginner's Reference - New Tank Syndrome

[ongchi8]

i think its not the media.. i encounter this problem before using different media...

i post that thread on the stingray forum..

i fell frustrated so i reset my tank using new media, suspecting that it might be the media that cause my ph to rise... but here it goes again.. the same problem

there should be something wrong with my water... but i dont know

our water system at home has a water softener for the whole house... and pass by a carbon filter before it goes to a hose for my water change...

all my other tanks are ok with some arowanas on it..

only this tank with some rays previously occupying it has a problem...

does water softener cause it?
or the carbon filter?

but i have lots of friend hobbyist using it also and all of them are fine...