CaRx media, why am I seeing high alk?

[HuduVudu]

@Randy Holmes-Farley when I dumped the plenums the alk went down and then back up. Upon further investigation, I have determined it is the CaRx media.

General question ...
I am using live rock rubble from Walt Smith rock as CaRx media, and my assumption is that is from Fiji. I have a ton so it makes sense, my assumption is that it is balanced. I question that assumption now. Why would this rock produce such a high alk in comparison with calcium? Or maybe my balance was out of whack and it is producing appropriately? I added a Kalkwasser reactor to the tank and left the reactor to run. The alk went to 11.2 dKh the calcium was at 360ppm previously it was 10.2 dKh and 350ppm. When I let just the Kalkwasser reactor run and turned off the CaRx I got 10.2 and 340.

I have ReBorn on order, not sure if this will solve my dilema but thoughts would be helpful. Does the CaRx media make that big of a difference?

@jda

 

[Randy Holmes-Farley Verified Community Expert]

I suspect the calcium kit is just not good at registering the 7 ppm rise that would be associated with a 1 dKH alk rise.

 

[Randy Holmes-Farley Verified Community Expert]

The media type cannot make much difference except to the magnesium added in place of a small fraction of the calcium.

 

[HuduVudu]

I suspect the calcium kit is just not good at registering the 7 ppm rise that would be associated with a 1 dKH alk rise.

So your position is that the alk calcium is being maintained and that the previous difference is being carried over?

 

[HuduVudu]

The media type cannot make much difference except to the magnesium added in place of a small fraction of the calcium.

I am using the 2 little fishies Reborn magnesium in the reactor. I am not really getting much mag out of it. My reactor is running 7.2 pH (Hanna), this doesn't seem like it is enough to get a real melt on the mag.

I have been using magneisum carbonate that I use vinegar to dissolve to bring up my mag which was pretty low (1020ppm) to currently higher (1200ppm). Not sure if the acetate is causing a alk rise. I doesn't seem like it because I have paused for a couple days to let the acetate to break down and see if I get anything.

 

[Dennis Cartier]

The Walt Smith rock you are using, is the artificial type made with concrete? I thought he was known for being the first proponent of using man made rock made out of concrete.

 

[HuduVudu]

The Walt Smith rock you are using, is the artificial type made with concrete? I thought he was known for being the first proponent of using man made rock made out of concrete.

No, it is based on Fiji Premium.

 

[Randy Holmes-Farley Verified Community Expert]

So your position is that the alk calcium is being maintained and that the previous difference is being carried over?

I’m just suggesting the calcium kit is not accurate and precise enough to detect a lack of calcium delivery over this time period.