Montipora digitata question

[Diomedes]

Did you say your alkalinity was 4.0? This might sound stupid but is that in dKH? Because if it is in dKH then it should be around 8.0 to achieve maximum calcification. Also your M. digitata may not have enough trace elements (including mainly strontium and magnesium) that it needs in order to lay down calciferous layers. They need strontium esp. for rapid growth. I use only Salifert test kits (which I Slowly, Slowly aquired after months of eating Kraft Dinner) and have had a wonky reading or two come out of a Seachem IMO. I don't recommend dumping tons of trace elements in though...that can cause more problems than it solves. What are you using for maintaining your chemical levels? (Ca, Sr, Mg, I etc?)

Stephen