Alkalinity and Calcium Imabalance Problems

[C-Reefer]

Hey guys,
I have been dosing two part for about a year and a half now. I get good growth for the most part, and have happy corals and a happy tank. About 3-4 months ago I was chatting with a mentor and he mentioned that I should be dosing equal parts of Cal and Alk. I didn't know this, so I went on and looked into it and realized that yes, I should absolutely want to be dosing equal parts. I had been dosing inequal amounts of both but parameters were right where I wanted them and pretty stable. Ever 2-3 weeks I would check Alk and Cal and they would be within 0.3 usually for alk and within 30 for calcium. I would then go ahead and adjust the doser a few ml to raise or lower whicever one. Fast forward to when I started dosing two part equally. Alkalinity initally stayed pretty stable at 8.3, before slowly starting to tank. However, calcium was always in the 470 range. I would bump up both equally and alk would even out but calcium would go up. I know I'm nowhere near the balance of around 8,3 alk/420cal.

For about the past two months sadly I had been neglecting my tank, I have been slammed with work and a lot of big decisions nd the tank just got fed. I had a cualerpa problem that took over the tank and a bit of GHA. Parameters when I tested were OK, but not great. Alk would hover around 8,0 and calcium would be aroud 500. Corals eventully started bleaching and I lost a few sticks. A few days ago I finally realized I had let it go way to far and did a 80% water change, stodcrubbed all the rocks, reset the tank basically. These past few days everything has been looking insanely happy, bleached corals are recovering, etc. However, I tested the day after the water change and alk was 6.7 and calcium was 470. Wierrddd because I had just done a massive water change with a brand new container of Fritz Blue Box (my reg). Every time Fritz has tested out money for me at alk 8.3, calcium 420, mag 1420. Today I tested and Alk was up to 7.3, calcium up to 500, and mag was 1380. I haven't touched my doser from what it was at before.

Why are my Alkalinity and Calcium not balancing out? This is not just from the big reset it has been an ongoing problem ever since I swapped to equal part dosing. For reference, Phosphate is 0.086 from a Hanna Checker, Mag I like to keep at 1420 but it will range down to about 1380 before I dose up, Nitrate is 2. Also, I mix my own DIY two part using Baking Soda and Dowflake Ice Melter. I'm thinking the DIY may be the problem but I'm not sure if I should go back to dosing whatever is needed to hit parameters I want, or just leave it and let it settle out on its own even if it's sitting at alk 8.3 and calcium 500. Thank you!

 

[reefwreak]

They don't balance out. It's a hobby myth that Randy has addressed in his old reefkeeper magazine articles posted on RC. The reality is that biological processes use the two up separately, and so they're not aligned. Most people who dose two part have to have a slightly higher dosing schedule for their alkalinity than their calcium.

 

[C-Reefer]

They don't balance out. It's a hobby myth that Randy has addressed in his old reefkeeper magazine articles posted on RC. The reality is that biological processes use the two up separately, and so they're not aligned. Most people who dose two part have to have a slightly higher dosing schedule for their alkalinity than their calcium.

If you don't mind could you link that article? I read several articles from Randy saying to dose equal parts and that they should equal out. Previously I had been dosing higher amounts of Alk as opposed to Calcium. If this is true I will just manually dose to 8.3, find how much it drops the next day, and just up the doser by that amount. And just simply back off Calcium until it hits where I want it to.

 

[reefwreak]

Sure. Nothing a quick googling couldn't fix:

http://reefkeeping.com/issues/2004-12/rhf/index.php

 

[taricha]

They don't balance out. It's a hobby myth that Randy has addressed in his old reefkeeper magazine articles posted on RC. The reality is that biological processes use the two up separately, and so they're not aligned. Most people who dose two part have to have a slightly higher dosing schedule for their alkalinity than their calcium.

Mostly disagree.
From linked article...

So the first "deviation" from the rule of calcium and alkalinity balance really isn't a deviation at all. If an aquarist is supplying a balanced additive to his aquarium, and calcium seems stable but alkalinity is declining, it may very well be that what is needed is more of the balanced additive, not just alkalinity. This scenario should be assumed as the most likely explanation for most aquarists who should look for more esoteric explanations for alkalinity decline only if calcium RISES substantially while alkalinity falls. Likewise, if alkalinity is rising and calcium seems stable when using a balanced calcium and alkalinity additive system, the most likely explanation is that too much of the additive system is being used.

The real imbalance effects described later in this article take effect slowly, and are manifested over weeks, months and years.

I assumed the same thing. That my reef was weird and consumed more Alk than Ca, until I measured them both daily for months. Then you can see they are the same.

Takeaway from the article is that they actually are balanced barring unusual circumstances that make a very small difference over a long time and require careful evidence to demonstrate.

 

[ahiggins]

That’s been my problem in the past: I research too much and mess something up. To me, if your reef was happy-why would you change? I’m not blaming you I’m just saying we have all done things like this trying to better our system, to switch from something that works.
Sorry your corals bleached it’s hard losing little things we grow

 

[craigbingman]

They don't balance out. It's a hobby myth that Randy has addressed in his old reefkeeper magazine articles posted on RC. The reality is that biological processes use the two up separately, and so they're not aligned. Most people who dose two part have to have a slightly higher dosing schedule for their alkalinity than their calcium.

Wow.

In a reef aquarium with no net nitrification or denitrification, to a first order approximation, they do balance out. The two major processes that disrupt that are the formation of calcium-magnesium carbonates, and acid generation or destruction by nitrification or denitrification.

If you wanted to turn back time to before that "myth" started, and for which I am largely responsible, you would find utter chaos and a lot less success than we enjoy now. People were literally dumping sodium bicarbonate and calcium chloride into their systems with not even a guide as to what the correct ratio should have been.

 

[reefwreak]

If you wanted to turn back time to before that "myth" started, and for which I am largely responsible, you would find utter chaos and a lot less success than we enjoy now. People were literally dumping sodium bicarbonate and calcium chloride into their systems with not even a guide as to what the correct ratio should have been.

Hey, after a 30 second google of who you are, I absolutely defer to your judgement. Please share an article or reference to use going forward. I don't mean it sarcastically at all either (though that sounds sarcastic, sorry), you're the professional, you have the PhD in this subject, I defer to your judgement and reference hands down. The discussion here already provided me with enough justification to no longer consider the myth, and affirm that 2 part in correct dilution/concentration should by and large support a reef tank dosed in equal parts.

I found this article in my googling, it seems very helpful as well. Thank you for your work providing half of the citations for the article. https://www.advancedaquarist.com/2003/2/chemistry

 

[C-Reefer]

So I'm more confused now... Should I be dosing equal amounts? I backed off on Calcium and raised Alkalinity and now Alk is 6.7 and Calcium is 450. This is from 5 days before when I changed them when Alk was 7.3 and Calcium was 500. Should I continue bumping up Alk and decreasing Calcium? Or dose manually to get them to alk 8.3 and Calc 420, before starting to dose equally at my consumption rate again?

 

[taricha]

So I'm more confused now... Should I be dosing equal amounts? I backed off on Calcium and raised Alkalinity and now Alk is 6.7 and Calcium is 450. This is from 5 days before when I changed them when Alk was 7.3 and Calcium was 500. Should I continue bumping up Alk and decreasing Calcium? Or dose manually to get them to alk 8.3 and Calc 420, before starting to dose equally at my consumption rate again?

I'd do an adjustment to get them where you want, then equal parts from there on.

 

[craigbingman]

I'd do an adjustment to get them where you want, then equal parts from there on.

So I'm more confused now... Should I be dosing equal amounts? I backed off on Calcium and raised Alkalinity and now Alk is 6.7 and Calcium is 450. This is from 5 days before when I changed them when Alk was 7.3 and Calcium was 500. Should I continue bumping up Alk and decreasing Calcium? Or dose manually to get them to alk 8.3 and Calc 420, before starting to dose equally at my consumption rate again?

So the first thing you need to do is an adjustment to put things "into the box" of near S=35 seawater calcium, magnesium and alkalinity. After that using equal amounts of balanced two-part supplements (or three-part) should keep things relatively stable. Again, probably no two systems are exactly the same in terms of magnesium demand to support mineralization, and nitrification, so it isn't possible to devise a single supplement that will keep everything in line for all systems at all times.

 

[craigbingman]

2 part in correct dilution/concentration should by and large support a reef tank dosed in equal parts.

"By and large" being a really important part of that statement.

I recently had a good reason to take a stroll down memory lane to the late 1980s and early 1990s, and it wasn't pretty. People were really doing their best, but without some guidance on the appropriate stoichiometry, were literally sometimes creating white-out conditions in their systems where calcium carbonate was crashing out of solution, right out of the water, usually mid-to late-day when photosynthesis was rolling, pCO2 was down, and temperatures were as high as they were going to get. That really stressed the corals, who often responded with a slime-storm, and sometimes a full system crash ensued.

As far as definite references for this, unfortunately my thoughts were serialized monthly and a bit spread out over several of the articles you have found. At about the time I started writing, Brockmann wrote a significant English-language treatment of the equilibrium relationships involved and published it in Aquarium Frontiers, I think in 1995. Somewhat after that, I started using the calcium/alkalinity diagrams you see reproduced and adapted in various places that explain the corrective actions needed to get things back into the box. The only place I've seen that generalized to cover Ca,Mg,alk in 2D projections and an interactive 3D plot, with all three responding to a fully realistic mineral demand was in a MACNA talk I gave around 2011. I'm pretty sure that will be refreshed and showing up on video in the not-too-distant future.

 

[Sarah24!]

Hello,

Not disputing the idea of equal dosing alk and calcium. However with that said every tank is different and the corals evolve to their ecosystem. There have been months on end where I dosed 1.5 of Alk and Cal daily every day was the same thing. Then suddenly it stopped, corals still did fine, but alk would drop every day and calcium would stay at 440. It has come to the point where calcium would move all over and alk was stable. Yes getting them back to 8 and 440 I have to dose out of sync. (I manually dose everything so I know exactly how much goes in). But when this occurs, it would be unwise to keep dosing equally. Since all systems are different and corals are living organisms, they do go through growth spurts and also have times where they are inactive. I try to keep my alk at 8 and cal at 440 every day, however sometimes I may have to dose 1 tablespoon of calcium and none of alk or maybe .5 of a teaspoon to make it back to 8. If I dosed the same amount my alk would spike rapidly which in most of our experience kills the corals.

It’s also noted that yes parameters need to be stable but if kept too stable it hinders the immune system of the corals. Allowing very small swings has shown to increase the health of the corals. What some fail to see is that my tank won’t be the same as my friends or anyone’s.
They can be similar and we can try ideas, but it’s like saying every human will respond exactly the same way to a certain medication. We know this is not true and every human (let’s say are diabetic), their amount of insulin will vary based on their body and habits and blood sugar. How can we even say this should always be done when we know they are a simple organism, but just through tanks on here look at the number of variables one has to consider?

If we want parameter of alk at 8 and cal at 440 then test them and manually dose (do the math) and add the amount to keep those parameters. Because sadly, that’s what the corals or aka living organisms respond to.

Another example is this ideal of suoer low nutrients for sps. I have seen and have pics of sps dominant tanks just doing amazing and they have .75 phosphates and plus 40 ppm nitrates. It’s because those corals in that tank have adapted to those parameters. If we drop them to a low nutrient system, then it stresses them and they die. People should care for their tanks and corals based on what their corals need. I have never consistently dosed my Alk and Cal the same amounts. Yes for a long time 8 months maybe a 12 months it was a daily given, I never tested and when I did it was always 1.5 tablespoons of each. Then suddenly the next day calcium stayed at 440 alk dropped to six and brought it up. Now I test daily to make sure Alk and Cal or 8 and 440, but the dosing is off. Not be a lot but it’s far from equal and yes my corals aren’t growing as fast. But it’s not abmormal for growth spurts to stop.