slowjazz;704826 wrote: I also agree and would add that in a way the you can use this to your advantage. (I did anyway)
If you take notice to where the Cyano has settled, it will give you a visual on your flow. By the looks of it and the rocks on the side, I would say you have a good dead spot there.
If you move the flow now, you can still use some of the Cyano to get a visual on what changed and then vacuum the sand. (once you cycle and the parms are back the Cyano should go away) It may sound strange to do this, but if you do nothing then in the future you will have waste and other junk settling in the same spots.
btw.. I'm assuming this just started? (looks like it) If so, don't freak out in a few days when all you see is red