I have always dosed Magnesium and have tried to keep the levels about 3X what the calcium levels are. I have recently switched to a Calcium REactor in my new tank and I have added Magnesium to that as well, so I no longer need to dose it per se, but it rather gets dissolved similarly to the calcium.
I think it's also important to do for Potassium. K+ greatly enhances the blue/purple colors in the corals. Having said that....this is, of course, not as important to dose until you actually have corals. I started a whole new system this fall and moved many of my corals over in November. Many of my
acroporas were more a brown color in my old tank (MH +
T5s). My new system is only
T5s, which I really like. My corals all seem to like the light and have grown significantly since the switchover. However, over Xmas I began to dose potassium....within weeks, some of my
acroporas have taken on unbelievably intense blue and purple colors. At the time, that was the only thing that I had changed in my system. I am now a firm believer in the need for potassium supplementation. I do also measure this as well, but it's been fairly difficult to get too high of a concentration. I think it gets used up fairly quickly.
Iron is another important supplement, but care must be taken to not overdose. Iron is important for bringing out a lot of the green colors in corals and I have noticed an increase in intense green in my coral polyps and tissue, since having started to dose with iron.
I also dose ZeoSpur2, which is a trace element supplementation. It's supposed to be helpful in controlling the amount of
zooxanthellae in the coral tissue to bring out more intense coloring.
I have switched over to all the ZEOvit supplementations. They are pricey at first...the acquisition of the substances...but, you don't really have to dose much. They are pretty concentrated, so the bottles go a long way.
