SOS PH crash!! need advice.

[terror]

just tested my tanks ph and it was at 3 already :( lost 3 fish already. luckily my arowana is still ok, except the eye seems to turned cloudy and injured.
i've added a little baking soda, how do i bring up ph safely and how much corals should i add or baking soda to bring up ph safely and gradually.

need help urgently .

thanks.

[liv2padl]

adding chemicals in the form of coral or baking soda (both are carbonate based) is only putting a bandaid on your problem. you need to figure out WHY your pH crashed.

what's the pH of the water out of the tap?
how often do you do water changes?
how often do you vacuum the gravel?
how long has the tank been running?
what size is the tank?
how many fish are in it?
what size are the fish in it?
what kind of fish are in it besides the arowana?
what are you using to test the pH?
how old is the test kit?