I don't know how you guys can have such high turnovers with LPS...?? As soon as I add another small powerhead I get poor polyp extension no matter how I try to arrange the powerheads. I just re-did my entire tank and I didn't have any powerheads in it for 24 hours and had the best poylp extension on the LPS I've ever had. I added my Koralia 2 which is blasting straight onto my SPS and only very indirectly hitting my LPS, and the poylp extension is definately a bit less on the LPS, although obviously my SPS are happy 'as a clam'.
