[slief]

If I am not mistaken, the 525XL is about 140 gallons. If that is the case, while the SM200 is an absolutely great skimmer, wouldn't be a great choice. I wouldn't recommend that skimmer for anything under a 200 gallon display with a truly heavy fish load.

The best choice would be a Double Cone 180. It will be a very consistent skimmer that will perform great and it's much less than the SM200! You really want a skimmer that is appropriately sized that works hard than an oversized skimmer that hardly has to work. These skimmers are very underrated and perform much better when the load matches their size. If you were to go with the SM200, you would need to run it pretty wet to keep it consistent. That means keeping the line where bubbles turn to foam up higher in the neck and also likely running the pump speed high than normal. For a 200 sized skimmer, I normally suggest 28-32 watts. You might need to be closer to 38 watts but because every tank is different, you will need to play with the speed setting to find the point where the skimmer remains consistent and also produces the most dense foam. The key thing to realize is that as the skimmer size grows, so does the neck diameter and volume of the neck. The larger the neck, the greater the amount of dissolved organics/proteins needed to generate enough foam to fill the neck and spill over into the cup. Raising the water level/foam line up further into the neck helps reduce the volume of the neck and allows the skimmer to perform more consistently in the absence of enough DOC's. Thus, to get it to perform consistently, you will need to play with the settings and the level inside the skimmer to find a point where it remains consistent.