positive side is less work, negative side is less control. you said you wanted multiple strains and i assume you want multiple stages (perpetual harvest). having a res for each tray is ideal because it lets you control the nutrients to a maximum level however if you want to use only 1 res it can be done

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Far from the twisted reach of crazy sorrow.Yes, to dance beneath the diamond sky with one hand waving free,Silhouetted by the sea, circled by the circus sands,With all memory and fate driven deep beneath the waves,Let me forget about today until tomorrow.