Dosing calcium and carbonate separately (a video to help Klemmetsmo reefing)
For klemmetsmo reefing. I hope this video is helpful.
When your levels of calcium and carbonate are in the safe zone, you can say your levels are balanced. If calcium is between 380 and 450, then carbonate can be any level you like between 7-11 DKH, to have a balanced ratio of calcium and carbonate. Only if one level is significantly out side the safe zone, or one level is below the safe zone, and the other level is above the safe zone, are your levels of calcium and carbonate are unbalanced.
The easiest way to correct this situation is, just let calcium levels fall naturally on there own. You could do a 50 % water change. Easy in a small tank, but not so easy in a large tank. This might stress the corals out more than the high calcium. If no or very little calcium is being used then a large water change might be the quickest way to restore levels..Most corals can stand levels of 500ppm calcium for short periods.
High carbonate is different. When carbonate levels hit 12-14DKH corals start to die, so unless your carbonate levels are dropping quickly, you might need to do a large water change.
When adding any calcium and carbonate to your tank you need to insure your magnesium levels are 1260-1350ppm.
Understanding calcium and carbonate in a reef tank can be difficult. More often than not, your levels of calcium and carbonate will be in the safe zone, and any corrections are easy. It is only when one, or the other, or both fall way outside this zone that we run into problems trying to correct levels. You might need to add one before you can add the other, or do big water changes to correct levels.
High carbonate levels (11-12 DKH) can increase the growth rate of your hard corals. The same can not be said of calcium.
When using a calcium reactor, or kalkwasser, you can not add calcium and carbonate separately using these methods. If you want to raise levels of one and not the other, to get your calcium and carbonate levels in the middle of the safe zone, you can just dose calcium or carbonate solution from a 2 part, providing one or both of your levels dose not fall way outside the safe zone.
There will be times when the ratio of calcium and carbonate use in a reef tank is not exactly 10ppm for every 1.4 DKH. The difference is only slight, and will only show up over time. 1 to 4% of the calcium can be replaced by magnesium. This will depend on the individual corals in your tank. Most 2 part manufactures know this and offset the ratio slightly to reflect this.
Some bacteria in your tank, can brake down the carbonate to create a carbon food sauce. The level of carbonate lost is often very low, and not worth worrying about. The extra los of carbonate compared to calcium in this case, will only show up over time as the level of loss is often tiny.