How do i change the ph in my Tank

[justanotherbozo]

i have a 45 ltr tank the water in my tank is near 7.0 ph.
my question is should i renew all the water or can i add the ph down to the tank.
thanks for any advise.:rastasmoke:

yeah, you can add the ph down to the tank

if you want the long answer, you need to post more info, and a pic or 2 wouldn't hurt