Cyano breakout during/the end of Cycle

[Myka]

Are you sure you're not experiencing dinoflagellates? Do a Google search and see what you think. Dinos look very similar to cyano, except dinos are more "snotty" than cyano is. Dinos tend to be caused by low flow combined with abnormally low pH. Do you know someone with a digital pH meter that can test for you? pH test kits aren't very accurate.

If it is dinos, I would suggest you re-start the tank since you don't have anything in it yet. Dinos can be VERY troublesome. You can either purchase new rock, or give the old rock a vinegar bath to kill off the dinos. In the future, if you see this starting up in a skimmerless tank, add an airstone or point a powerhead at the water surface which will help to raise the pH by off-gassing the CO2 in the water.

If it is cyano, you can pull the rocks out and swish them in a bucket to get it off. It comes off easily. Then use a piece of rigid airline with a piece of vinyl airline on it to siphon it off the sand. The BEST method to be rid of cyano is to physically remove it. You will likely have to do this several times over several weeks.