all readings are 0!

[sandcarrot]

all my readings are 0, ph is 8.2, do i change water now? how much? also i have some of that red algea on my live rock...
what should i do

 

[col]

All readings are 0 - which readings?
Have you cycled the tank and if so you should have nitrates.
Have the ammonia and nitrites risen and fallen?