Phosphate control on large systems

[Wrench]

For all of you guys with huge systems, how do you control phosphate? A good friend of mine has a 2100g system (1000g reef, 750 FO plus sump etc) and we're trying to work the bugs out of it. Right now there are around 40 fish several of which are around 12" or so. Phosphate is hovering around .4ppm.

Aside from costly GFO and liquid binders, are there other methods that may be more cost effective? We're not opposed to using either, it's just that GFO will run about $300/month minimum for a system this size.

Thanks!

[SeanT]

Great skimmer(s), water changes, "cooked" rock, to name a few.

[Nanook]

I have about 1100 gallons and rely on GFO heavily. I was vodka dosing but have stopped that method and will rely on refugia with macroalgae and GFO....pricey but it works.