Low alkalinity high calcium with Reactor

Buh Buh Bacon · Feb 28, 2018

I currently have slightly low alkalinity between 6.4 and 7 and high calcium (a little over 500). Things in the reef are thriving. I have heard you can set the reactor for the desired alkalinity and the calcium will fall into proper range since it’s all about balance. pH is fine (maybe a little low at 8.1) but hesitant to do anything about it since corals, fish and inverts and everything are healthy and happy. Reason I’m asking is I’d like the alkalinity to be higher just on personal preference and the alkalinity to be lower. Is it possible the reactor size in an issue as it’s a relativiely small one for the 140 gallon tank? IE if I was to go with a bigger reactor would the alkalinity and calcium fall into where I want them to be?

Brew12 · Feb 28, 2018

Buh Buh Bacon said:
I currently have slightly low alkalinity between 6.4 and 7 and high calcium (a little over 500). Things in the reef are thriving. I have heard you can set the reactor for the desired alkalinity and the calcium will fall into proper range since it’s all about balance. pH is fine (maybe a little low at 8.1) but hesitant to do anything about it since corals, fish and inverts and everything are healthy and happy. Reason I’m asking is I’d like the alkalinity to be higher just on personal preference and the alkalinity to be lower. Is it possible the reactor size in an issue as it’s a relativiely small one for the 140 gallon tank? IE if I was to go with a bigger reactor would the alkalinity and calcium fall into where I want them to be?

Did you have everything in balance when you put the reactor online?

Denisk · Feb 28, 2018

Does your calcium continue to rise?

You want to tune your calcium reactor based upon your alk consumption.

GoVols · Feb 28, 2018

Welcome to Reef 2 Reef.

I caught an article about balancing out cal to alk with a cal calcium reactor and it had some of Randy's quotes in it.

It said that one thing to look at was to make sure that your reef as not lower than .35ppt in salinity, when running a cal reactor.

dimo · Feb 28, 2018

The high calcium is probably coming from your salt mix and is kept extra high due to water changes. I have that same issue. Currently using RC which tests over 490 freshly mixed. When my current supply runs out I'm switching to a salt with less calcium.

krausean · Feb 28, 2018

As far as I know, it's normal for levels to go out of whack over longer periods of time. Corals, inverts, and other things depending on calcium & carbonate don't necessarily uptake the same ratio of alk/cal as the reactor spits out. Also, check your Magnesium level, if you haven't already.

saltyfilmfolks · Feb 28, 2018

dimo said:
The high calcium is probably coming from your salt mix and is kept extra high due to water changes. I have that same issue. Currently using RC which tests over 490 freshly mixed. When my current supply runs out I'm switching to a salt with less calcium.

This I believe.

GoVols · Feb 28, 2018

@dimo @saltyfilmfolks
Good point.
I do use a salt mix that mixes to my reef's (and cal reactors) parameters, at .35ppt

Randy Holmes-Farley · Feb 28, 2018

What media are you using?

If it is lower in magnesium than the calcium carbonate that is being deposited in your tank, high calcium will result long term, just as it does dosing limewater/kalkwasser for calcium and alkalinity.