Been reading a lot of the previous threads on this filter and stole one of Richard's ideas.

I've reworked the sump and took the Hiatt off the main return pump. It's now fed by a dedicated mag 12 that takes water from the one end of the sump and returns it back to the other end. From Richards posts, this is how the filter is used in commercial settings. I'm hoping this will keep the tank from getting too sterile. We'll see.

I measured the flow rate and it's almost 1000 gph. Snake advised that the 10X flow rate is important for obtaining the optimal DO content of 8+ mg/L. This level is the optimal range for his bacteria to consume waste at the fastest rate.

Why did I do all this? Well to be honest, I started seeing a little hair algae on the gravel and on a few rocks. NO3 was still fairly low, so I tested for PO4. Bam, saw some detectable phosphates. One of Richard's older posts said the carbon used in this system contains a higher phos level since it's not cleaned the same way as regular carbon.

So, I reinstalled my po4 reactor and made the above changes to the sump. I also turned the skimmer back on. Within a few days of all this, the algae started to thin out, and I only have a few receding spots here and there. PO4 levels have dropped back to undetectable and nitrates fell back to below 10mg/L.

The skimmer pulls very little skimmate since the RN! bacteria take care of most of the fish waste. All fish seem very healthy and I've seen my mystery wrasse develop some pretty colors on his dorsal and anal fins since adding this filter.

The sps still have great polyp extension and overall the tank looks pretty good.