When aquariums become overgrown with corals, the water flow pathways are severely restricted if the pumps are left alone and go unmoved. The corals won’t grow into areas of direct water flow, but will stay on the periphery and eventually block water flow from reaching other places in your aquarium. To fix this, pruning your corals will certainly help. I don’t necessarily recommend moving the pumps, as the corals have become adjusted to water flow in its current state. If you move the pumps, you could potentially blast a coral with too much flow, causing tissue recession or coral death.