Calcium and Alkalinity

[WayneO]

I just got a set of LaMotte test kits.
My Calcium was 421.8 ppm and Alkalinity 460ppm/25.6dKh
I did the Alkalinity test twice with the same result.
Any suggestions on what I can do to correct this?
I was going to add Kalkwasser to correct the Calcium but won't this
raise the Alkalinity even more?

Welcome to AquariumAdvice.com

I would suggest you have the test verified by the LFS or other test kit. That is an increadibley high number and may be the result of a faulty test kit or operator error. Either way, accuracey should be determined. I would also suggest testing some newly mixed SW as a means of verification. If it's "all good" with the new SW, I would suggest a few 15-20% water changes over the next few days to get the chemistry back in line.

Have you been dosing any buffer products prior to getting your test kits and how old is the tank?

Cheers
Steve

[Electrobes]

what water do you use Wayne? Are you using tap water or RO water?

[TheMadNucleus]

Yikes! - This may be a stupid question - but what were you testing: Tap Water or Tank Water.

In addition to the suggestions above, here are some of my thoughts.

No on the Kalkwasser (BTW the literal translation of this, from german to english, is "Chalk Water" - better known as Lime Water). I'm pretty sure this will most likely make matters worse at this point.

If it is your tank water that you posted the stats on - then test your Tap water and compare. If it too is very high then you have a supply problem (You do not mention if you are RO'ing your water - this will take much calcium out as calcium molecules are to large to pass through the TFC). If you are RO'ing your water it may be time to replace your TFC, sendiment cartridge and carbon element.

Also be aware of some hidden causes of high gKH and dKH: Substrate (some are very high in calcium and carbonates), Decorative items (some rocks and stuff contain limestone, etc), chemical additives you might be using - i.e. buffers, etc.

One buffer product I know of instructs users to add x tablespoons every water change. This is pretty bad advice as it is intuitive that you should only do this if you need additional buffering. Wholesale addition of this kind of product can cause trouble.

HTH

Tom