can any one advise me i have just set up 135gallon feef tank people keep telling me not to add the sand at this stage if i do i will never get rid of the algea are they correct or can i put it in now
Welll ... you didn't really say what exactly you have set up but in any aquarium I have put the substrate in first because I don't like pouring it through the water and fouling it all up.
Also, I've never heard anyone say to wait on sand. Just my 2 cents.
Depends on what you do next, it *may* be not a good idea to add sand right now. For example, if you need to cure live rock on the tank, having the sand in there make it more difficult to drain and do water change during the curing process. Other than this, I can't think of any reason not to add sand right away...
Did those "people" tell you any reason for their suggestion? How is that related to algea problem?