I see, interesting. Yeah, like littlesilvermax, I too am curious what pH recommendation and media is used on the Deltecs.
With the Schuran reactors I think the recommendation is to use a pH in the 5's
(I could be wrong, it's been a while since I read up on those) and a much larger grained crushed coral as media. Perhaps Deltec's are like this as well. I know Deltec uses the term "fluidized" a lot when describing their reactors and I thought this meant they use an upflow instead of downflow through the media.