You can point them towards the front, center of the aquarium. You could also aim them at each other across the tank to create turbulence. It really depends on how things are arranged in the tank. It takes some fooling around w/ to get it how you like. A good way to picture the flow is the polyps of the SPS
should look as if they are swaying in a gentle breeze.
DT's, or other LIVE phyto such as phyto-feast, will give the best results if you decide to feed phyto. As mentioned it depends on the size of the clam, as to whether it is absolutely necessary or not. Other non-refrigerated, dead planktons IMO
/IME tend to pollute more than they help.