All xeniidsare autotrophic, i.e., they produce their own food and do not capture food from the water column. In fact, they don't contain any digestive capacity. As far as pulsing, there is as yet no generally accepted theory on why they exhert energy to pulse. Pulsing has ben most closely associated with Ph levels and they appear to respond the best tp ph over 8.3. Iodide can help but should only be added if one is prepared to test since toxicity can develop. Xenids can do well in almost any flow condition but too much direct flow may diminish pulsing.