Noob reef chemist - dosing Alk - should I still dose Calc?

[findingsimple]

My tank is about 4 months old. For the past month (maybe closer to 2) I've been dosing Alk to maintain stability at around 8dkh.

Currently I'm up to dosing to add 0.5 dkh a day using Red Sea Foundation B KH/Alk.

I don't dose any Calc and test it roughly once to twice a week (using a Hanna checker).

Past results have been:

456 (today)
462
459
460
476
484
473
475
484
481
481
455
484
468

I do nightly water change ~7L for a total weekly roughly 10% of my 500L display.

I understand there is a relationship between Calc and Alk consumption and its been niggling on my mind that something isn't quite right for a while. @vetteguy53081 here suggested my Calc might be low but I've never tested low number.

I've been looking around for possible causes/answers and stumbled upon @Randy Holmes-Farley 's post When Do Calcium and Alkalinity Demand Not Exactly Balance? - which has some great info and possible causes for the imbalance.

For me I guess one possible cause for the imbalance is ,my water changes - but it still worries me I'm seeing "pitted skeletons"

I see quotes like "After two days, many aquarists might conclude that they need additional alkalinity, when in reality, they need more of both calcium and alkalinity to stabilize the system." and it makes me wonder if I should just been doing Alk and Calc.

Does anytone have advice on whether I should incorporate a more balanced approach to my dosing? More calc etc.

Thanks in advance.

 

[gbroadbridge]

My tank is about 4 months old. For the past month (maybe closer to 2) I've been dosing Alk to maintain stability at around 8dkh.

Currently I'm up to dosing to add 0.5 dkh a day using Red Sea Foundation B KH/Alk.

I don't dose any Calc and test it roughly once to twice a week (using a Hanna checker).

Past results have been:

456 (today)
462
459
460
476
484
473
475
484
481
481
455
484
468

I do nightly water change ~7L for a total weekly roughly 10% of my 500L display.

I understand there is a relationship between Calc and Alk consumption and its been niggling on my mind that something isn't quite right for a while. @vetteguy53081 here suggested my Calc might be low but I've never tested low number.

I've been looking around for possible causes/answers and stumbled upon @Randy Holmes-Farley 's post When Do Calcium and Alkalinity Demand Not Exactly Balance? - which has some great info and possible causes for the imbalance.

For me I guess one possible cause for the imbalance is ,my water changes - but it still worries me I'm seeing "pitted skeletons"

I see quotes like "After two days, many aquarists might conclude that they need additional alkalinity, when in reality, they need more of both calcium and alkalinity to stabilize the system." and it makes me wonder if I should just been doing Alk and Calc.

Does anytone have advice on whether I should incorporate a more balanced approach to my dosing? More calc etc.

Thanks in advance.

0.5 dKh weekly Alk consumption will result in approximately 3.4ppm Ca consumed in the same period.

Now the measurement uncertainty of the Hanna Calcium checker is about 5% so todays reading of 456ppm could really be anything from 434 to 478 ppm. Effectively all those readings are the same reading .

Of course you are replenishing Alk and Ca with the water changes, so I really wouldn't bother too much about the Calcium until your consumption is significantly higher.

You could if you wish dose the appropriate amount of Ca, if you have the equipment to automate it.

 

[Randy Holmes-Farley Verified Community Expert]

Have you used that checker on your new salt water?

The Hanna calcium checker is prone to issues.

 

[findingsimple]

Have you used that checker on your new salt water?

The Hanna calcium checker is prone to issues.

I will tomorrow - anything in particular i should be looking for? I’m guessing that it matches the bucket and/or isn’t just giving me the same readings again?

 

[findingsimple]

0.5 dKh weekly Alk consumption will result in approximately 3.4ppm Ca consumed in the same period.

Now the measurement uncertainty of the Hanna Calcium checker is about 5% so todays reading of 456ppm could really be anything from 434 to 478 ppm. Effectively all those readings are the same reading .

Of course you are replenishing Alk and Ca with the water changes, so I really wouldn't bother too much about the Calcium until your consumption is significantly higher.

You could if you wish dose the appropriate amount of Ca, if you have the equipment to automate it.

Just confirming I mentioned 0.5 dkh daily consumption - (you mentioned weekly)

 

[Randy Holmes-Farley Verified Community Expert]

I will tomorrow - anything in particular i should be looking for? I’m guessing that it matches the bucket and/or isn’t just giving me the same readings again?

If it reads substantially higher than expected for the salt mix and the measured salinity, then you can conclude one of two things that may explain the calcium not dropping much:

1. The checker is reading high
2. The salt mix is unusually high in calcium (either by an off batch, a salinity mismeasurement, or settling in the batch).

 

[gbroadbridge]

Just confirming I mentioned 0.5 dkh daily consumption - (you mentioned weekly)

At that level of consumption, I'd be considering setting up automated dosing of a balanced two part additive.

 

[findingsimple]

If it reads substantially higher than expected for the salt mix and the measured salinity, then you can conclude one of two things that may explain the calcium not dropping much:

1. The checker is reading high
2. The salt mix is unusually high in calcium (either by an off batch, a salinity mismeasurement, or settling in the batch).

Got up and tested. Reading is 470. I'm using Red Sea blue bucket which is supposed to be 415-445 (I usually have to use a little more than directions to get 1.026) so I'd say it's probably fairly close (maybe?)

 

[findingsimple]

At that level of consumption, I'd be considering setting up automated dosing of a balanced two part additive.

I've got Alk on a doser and 2 other pumps free so that won't be an issue - I just want to make sure I'm not going to overdose etc.

 

[findingsimple]

0.5 dKh weekly Alk consumption will result in approximately 3.4ppm Ca consumed in the same period.

Would I be making ~3.4ppm back from a 7L water change each day?

 

[findingsimple]

My current bottle of alk is just about finished so also wondering if I should just upgrade to 2 / 3 component solution while I am replenishing things

 

[gbroadbridge]

My current bottle of alk is just about finished so also wondering if I should just upgrade to 2 / 3 component solution while I am replenishing things

Have a look at Randy's recipes.

Many folks use them very successfully.

https://reefkeeping.com/issues/2006-02/rhf/index.php

 

[gbroadbridge]

Would I be making ~3.4ppm back from a 7L water change each day?

If the Alk is dropping even after water changes, then the Ca will also be dropping, however it is comparatively smaller and thus harder to measure.

If you're using a balanced two part system , you dose based on Alkalinity results as they are easier to measure.

The Ca is replaced in the correct ratio that keeps everything (mostly) balanced.

 

[SPS2020]

If your tank is four months old, why are you dosing anything? Really shouldn't need any additives for the first year. What corals are in the tank? What size is the tank?

 

[findingsimple]

If your tank is four months old, why are you dosing anything? Really shouldn't need any additives for the first year. What corals are in the tank? What size is the tank?

Build Thread - My first reef - CADE 1200 S2/P

Added “Benny” the lawnmower blennie And “Mimi” the mimic tang (lemonpeel) Is that mimic tang as ridiculously tiny as it looks in the photo lol adorable

www.reef2reef.com

 

[findingsimple]

If the Alk is dropping even after water changes, then the Ca will also be dropping, however it is comparatively smaller and thus harder to measure.

If you're using a balanced two part system , you dose based on Alkalinity results as they are easier to measure.

The Ca is replaced in the correct ratio that keeps everything (mostly) balanced.

Thanks @gbroadbridge @Randy Holmes-Farley ill look into adjusting my dosing tomorrow

 

[vetteguy53081]

You have to develop a balance with alk and calcium. When this is met- your corals are showing good growth rate and steady consumption levels. There is a correlation between high alkalinity and reduction in calcium whereas higher calcium levels can lower alk. As calcium increases, so does precipitation of calcium carbonate and consumption will depend of type of corals you have and add. This is why often dosing two part works well for many as you can control the two together.

 

[findingsimple]

Deleted

 

[PeterEde]

I stopped using my hanna Calc checker after a few tests. I found it very inconsistent.
One day would read as I expect next something ridiculous.
I went back to redsea calc test. I trust it and my eye

 

[thatmanMIKEson]

I would forget the calcium checker for a while and dose calcium based off your alkalinity like @gbroadbridge said.

I dose Calcium chloride, and sodium carbonate in equal parts. I also use the balling c but that's besides the point an not exactly related.