Please read,
http://www.reefkeeping.com/issues/2002-05/sh/feature/
"Out of Balance
Another common problem when setting up a calcium reactor is getting a correct balance between calcium and alkalinity. A common complaint is as follows:
"I have an alkalinity of 3.5 mEq/L (10 dKH), but my calcium level is only 320ppm. I have tried adjusting the reactor, but cannot get the calcium level to rise without the alkalinity going too high."
A calcium reactor may be described as a 'balanced' calcium / alkalinity additive. Basically, this means that it adds calcium and alkalinity to the tank in the same ratio as is used by our corals during the process of calcification. Simply put, it is not possible to change the calcium level without the alkalinity being affected also in a defined manner.
As an example, for each 1 mEq/L alkalinity (2.8 dKH) the calcium reactor adds 20ppm calcium. If your tank starts out with 3 mEq/L alkalinity (8.4 dKH) and 320 ppm calcium, and you raise the alkalinity to 4 mEq (11.2 dKH) using the calcium reactor, then the calcium level will only increase to 340 ppm!
Natural seawater at 35 ppt salinity typically has around 2.5 mEq/L alkalinity (7 dKH) and a calcium level of 410 ppm, but I personally aim for around 3 mEq/L alkalinity (8.4 dKH) and 420 ppm calcium, and many others prefer even higher levels. Once you have decided on the levels, it is a useful idea to map where the calcium and alkalinity levels are (Bingman 1998) and then perform any corrections needed to get them back on target.
If the calcium level needs boosting, then I recommend using an additive such as calcium chloride. One gram of an anhydrous calcium chloride product (such as Turbo Calcium) will raise the calcium level by 360 ppm in 1 litre of water (95 ppm in 1 gallon of water).
If the alkalinity level needs boosting, then sodium bicarbonate can be used. One gram will raise the alkalinity by 12 mEq/L (34 dKH) in 1 litre of water (3.2 mEq/L (9 dKH) in 1 gallon of water).
In both cases, I recommend making changes slowly, rather than adding them all at once.
It is also worth noting that you may have difficulty achieving natural calcium and alkalinity levels if your salinity is less than natural seawater (35ppt) (Holmes-Farley 1998) or if you have a deficiency in magnesium (Bingman 1999, Holmes-Farley 2001). A solution to magnesium depletion, used by some aquarists, is to include a few teaspoons of pure dolomite in the calcium reactor where it can dissolve, adding magnesium to the tank (Bingman 1997).
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Thats nice you read the 101 on how calcium reactors work, but without having experience implementing them, you really don't have any ground to stand on here.
Also, you called me out because I stated they do not add calcium and carbonates in a balanced ,1:1 ratio.......The reason I said that is its because they don't.
Simple as that.
I think its also funny I mentioned earlier on ITT that calcium reactors do an awsome job of maintaining KH, but on high demand systems, they can fall short on calcium demands. I was then told by some on here " its must not be dialed in properly or not correctly sized then".
Nope, there is a reason the above article includes this common problem, and its solution???? dose CaCL.
I am not saying I am a scientist, or a know it all.
However, out of 17 years of experience with this hobby 8 of those years were spent working in it professionally, at one point I was maintaining 27 different reef aquariums. Reef aquariums, day in, day out.
The result? I have quite a bit of hands on experience with different techniques, see the difference in systems, pieces of equipment, problem solving etc etc.
Guess, what? sometimes it doesn't always work out how its supposed to in the book or article you just read and products don't always perform as the owner manual state.
Also,
Just thought I would share that little tid bit of hands on experience and problem solving for those running reactors.