I feed both floating and sinking, my fish eat both. But I need the sinking especially for my catfish. Only time I shut filters off is when I am feeding frozen foods. This way it doesnt get blown everywhere and more food gets in my fishes stomach rather than the filter.
I agree, syno cats rock. I feed both. start with floating for all the fatties that will sit up at the top and wait for the food to hit. After they are good and full, I will start the sinking to feed the rest of them. but my loaches will just come up to the top to eat.
I got sinking Hikari at home for the same reason you do.
I haven't had that much success with getting my fish to eat it. They will eventually, but it takes time and I feel like it just makes my sand look messy. Even my O's are quite lazy that way.