[Delphinus]

I used to think those numbers were perfect too, but it seems to me the current thinking is that an ideal alk is closer to about 3meq/l. Also, apparently with the current thinking on ULNS tanks (Zeovit, Ultralith, Plyplaps, etc.) that your target Alk actually "needs to be" in the 3.0 to 3.4 (max) range (I'm not 100% certain on this but I think I've heard that).

My main concern though was that I was finding that I was going well above 4.0meq/l, at one point I had an alk close to 4.8 meq/l. Things were looking pretty unhappy at that point.

However, since then I have backed off the reactor and the Alk seems to be settling in around 3.4. I'm happier with this although my metering pump that is feeding the reactor is dialed down to basically nil. I suppose that's OK but I'm always happier if I can have an adjustment knob set somewhere in the middle of its range rather than at one of the extremes (ie. if you listen to stereo and the volume is always set to 10 {out of 10} then something's not right. Similarly if you find it's "way too loud" and the volume is set to "less than 1" {out of 10} then again it's sort of indicating something's not optimal with the system, at least according to your tastes if nothing else). I dunno maybe I'm not making any sense here.

Anyhow so I was sort of thinking that my next step might be to dial it up to about 5%-10% but only running it at night. The nice thing is that to do that all I need to do is throw a timer on the feed pump.

I'm thinking that the situation is probably indicative of not having as high of a draw on calcium than I was expecting. I guess this is true, I peg my clams as probably the hungriest consumers of Ca and Alk. I don't have any SPS anymore, they just don't live for me (in the last year the longest I've had an SPS frag live for me is about 2 weeks. Actually, I guess that's not true, I did buy an abrotinoides that was hanging on after 4 weeks but it was trying to recede on me so I've asked a friend to house it for me until such time as I can just tear down this tank and move all my livestock into the new system).