You should put all your rock in before you start the cycle. It is better to go rocks first, then sand but if your sand is already in just make sure your rocks are set right in not sitting on top of the sand. In regards to the sandstorm, just find that sweet spot with your powerheads to reduce it - aim them up so they break the surface? It took me a while to find the right position for mine. It's just trial and error
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