So I have two large sinlarias in a 120. In the middle switching tanks and have removed one hob filter and the return pump from the sump. So I have eels and became concerned that the air stones and 500 gph hob were not getting enough oxygen down to the bottom. So I put in a powerhead. I do not have it flowing directly on to the sinularia but it has affected the flow to a degree that the sinularia closed fairly tightly. I shut off the powerhead. I know people put the flow right on sinularia. But I don't want to risk it. Mine is not used to it. What kind of flow does your sinularia like?