Kalkwasser and calcium/KH

[Bigfishy]

Its common for calcium levels in an aquarium to reach high levels around 500ppm with the dKH remaining around 5dKH but why if the one is using both a calcium reactor and kalkwasser all was okay durning the cooler months but now I have the issue due to higher temps therefore more ATO through the kalkstirrer. Temp between 25 and 25.2

As per Randy's Chemistry article kalkwasser is a balanced additive and so is the use of a calcium reactor.

My salt Salt mix has a calcium of 440ppm and dKH of 9 mag of 1340ppm, sg is 1.027 @ 25 deg celcius = 35.5ppt why would either the Kalkwasser or calcium reactor be causing the calcium to rise and kh to drop.

Confused as to why this is happening is the Kalkwasser less effective on raising kh levels within a aquarium with a calcium level of 440 ppm ,calcium reactor runs at around 45dkh (using rowalith C+) should I adjust this lower or higher

:headwally:

Which unit do I remove or what do I do, :hmm3:help.

IMO I think the kalkwasser is pushing the calcium up and driving the KH down. Kalkwasser was beening used to maintain ph @ around 8.1/ 8.2.
Am I correct in my assuption.
10% water changes done weekly.

[m2434]

That seems like a big difference. I would probably tend to assume some of the discrepancy may be testing error. However, there are reasons ca and alk may not balance. Randy describes them better than I though, so, here is a good link:
http://reefkeeping.com/issues/2004-12/rhf/index.php

[chuckreef]

I suspect the higher temp.'s are resullting in increased growth/calcification and that as result of that, it just appears that the alk is dropping faster than the calcium. (If the Ca was 520 or 530 before, which may be barley noticeable on the test kit, and dropped to 500 now, the two likley are fallling inline with one another. The drop in alkalinity just "appears" to be more dramatic.)

I would check everything is working properly, including the Ca and alkalinity test kits, and manually restore the alk with baking soda for a few days/weeks. See what happens.

Why are you using both a Ca reactor and a kalk stirrer?

[bertoni]

Kalk can't drive down the alkalinity without driving down calcium proportionately. I'm not sure what's happening in your system, but there might be some measurement problems.

I'd dose the alkalinity up to at least 7 dKH and plot the daily trend line.

Temperature at 25 C is bit low for a tropical reef. 28 C is more like normal.

[Bigfishy]

That seems like a big difference. I would probably tend to assume some of the discrepancy may be testing error. However, there are reasons ca and alk may not balance. Randy describes them better than I though, so, here is a good link:
http://reefkeeping.com/issues/2004-12/rhf/index.php

Wish it was testing error and similar results are being found with other reefers. This is being found on more and more aquariums here in SA. Levels being retested with two or three brands of kits. Great link and I may have something but Randy may know. But I think the alk is not returning to the system father the nitrogen cycle as the aquariums in question run bio-pellets and that removes nitrate by skimming therefore removing alkalinity. Correct me if I'm wrong.

[Bigfishy]

I suspect the higher temp.'s are resullting in increased growth/calcification and that as result of that, it just appears that the alk is dropping faster than the calcium. (If the Ca was 520 or 530 before, which may be barley noticeable on the test kit, and dropped to 500 now, the two likley are fallling inline with one another. The drop in alkalinity just "appears" to be more dramatic.)

I would check everything is working properly, including the Ca and alkalinity test kits, and manually restore the alk with baking soda for a few days/weeks. See what happens.

Why are you using both a Ca reactor and a kalk stirrer?
Temp still stabil within .4 of a degree via profilux or Aquatronica on various systems but the chiller is activated more than in cooler times. So no real change in temp.
Calcium reactor for the obvious and Kalkwasser for better ph, improved skimming and phosphate export.

[Bigfishy]

Kalk can't drive down the alkalinity without driving down calcium proportionately. I'm not sure what's happening in your system, but there might be some measurement problems.

I'd dose the alkalinity up to at least 7 dKH and plot the daily trend line.

Temperature at 25 C is bit low for a tropical reef. 28 C is more like normal.

Ruled out measurement issues by testing with 2 to 3 different brands of test kits and extremely close readings if not the same. I have always run temps at 25 C is this an issue and will Kalkwasser have a better effect on KH levels at higher temps I know the increased temp will certainly effect the ph and decrease O2 levels, and giving high stocking levels of fish this may be an issue.

[bertoni]

25 C should be fine. It won't make a difference as far as kalk. On the other hand, a higher temperature won't make a significant difference in pH, and I'm skeptical that the difference in oxygen saturation would be enough to cause any problems..

Other possible sources of alkalinity problems are:

1) tap water, which can contain calcium, magnesium, and alkalinity
2) pH buffers, which all add alkalinity
3) salt mix problems, such as differential settling, for a couple of water changes

I would dose the alkalinity up to a reasonable level, and continue dosing just alkalinity until the calcium comes into line, and watch carefully going forward. Baking soda would be fine for this purpose.

[Randy Holmes-Farley]

With the use of limewater, calcium can slowly rise if you add enough to maintain alk because some of the calcium added is substituted by magnesium in the naturally deposited calcium.

So by that same reasoning, if you somehow dose limewater exactly to maintain calcium, alk will have to fall since some of the alk is getting used up forming magneisum carbonate.

That is one of two big reasons to dose limewater by alk control, not by calcium control.

It is also a reason to do water changes and to not use a high calcium salt to start with when using limewater.