If its "live sand" then Id suggest you wait and actually return it for dry sand or thoroughly rinse and dry it to remove as much of the dead organics as you can...
Then add it whenever..
Even dry sand should be rinsed very well to remove small fine particles that WILL cloud the water and get on everything..
I can't return it...
https://images-na.ssl-images-amazon.com/images/I/91kQyMURZzL._SY879_.jpg
this is the sand. should i wash it so
Cyanobacteria is almost always one of a few things (or a combination of them).
1. New tank uglies
2. low flow
3. excess nutrients
4. exposure to sunlight (I find this especially a problem in the fall/winter)
Wait out the uglies.
Increase flow by adding one or more power heads to help randomize the flow.
Remove the source of excess nutrients - either by decreasing the feeding, water changes, or allowing the rocks to fully mature (they may be leeching PO4)
Block the sun from hitting the tank, especially if near a window.
Manual removal isn't usually too hard. Siphon out as much as possible during your regular weekly water changes. If that just isn't working, then Chemiclean will work wonders, but it will only fix the symptom, not the problem.
If its "live sand" then Id suggest you wait and actually return it for dry sand or thoroughly rinse and dry it to remove as much of the dead organics as you can...
Then add it whenever..
Even dry sand should be rinsed very well to remove small fine particles that WILL cloud the water and get on everything..
may i ask you why would you rinse it? other tells me that as no sense to pay for a live sand and then wash all away
Because it likely contains a lot of dead organic material which will potentially make your problem worse... I would rather start with clean dry sand vs adding all of those extra organics to a problem tank..