Just keep blowing those rocks off with a turkey baster. I had the same problem. Blow hard into the holes, you will be amazed at how much gunk comes out. It even shoots out from the opposite side of the rocks. My flow was good but, I had a powerhead that was pushing waste away from my intake...
The other evening I noticed this worm streching out of my rock. It is an 1/8" - 3/16" in diameter and I have seen it coming out of the rock at least 3". It reminds me of an elephant trunk. It appears that the head is looking around on the surface of the rock for food. Good or bad? Let me...