ESV B-ionic 2 Part - equal amounts?

[Daniel91]

So I am about to initiate a week of daily testing to get latest consumption numbers for my tank.

I’ve never dosed before, so I am trying to start this off right. The more I look into it, there more confused I get. Half the people using two part says dose in equal amounts, others say either part based on tank consumption (which in my mind makes sense)

What’s the logic behind dosing equal amount if there is a higher consumption rate of one than the other?

 

[rkpetersen]

Theoretically, any balanced two-part will provide just the right amount of both calcium and alk for growing corals.
There will never be a higher consumption of one or the other due to coral growth, based on simple chemical stoichiometry.
Coral skeletons are made up of calcium carbonate (plug Mg and other elements, which can be ignored for now).
Calcium carbonate is CaCO3; one part calcium to one part carbonate alkalinity.
Abiotic precipitation of calcium carbonate on heaters, pumps, etc should also adhere to this 1:1 ratio.
However, this is the theory, but the experience of reefers is often quite different.
I have never heard a satisfactory and clear explanation of how an imbalance arises.
It does though, frequently, and usually results in a deficiency of carbonate alk, which requires increased dosing of that component.
I used to think that this was due to CO2 gas leaving the water, resulting in a drop in alk.
However the science indicates that alk content in saltwater cannot change in this way.
I suppose imbalance could be due to carbonate combining with other elements than calcium, but I've not heard specifics.
So, bottom line is that, if your starting levels are appropriate, you should start with balanced dosing.
But don't be too afraid to 'uncouple' the dosing if the need to do so appears to be present, based on future testing.
Also note that calcium reactors, which may be the best dosing method overall, always dose in the balanced ratio of 1:1;
this is because they dissolve already formed coral skeletons for both calcium and alk. (And this also provides magnesium.)

Here's another thing that isn't obvious and that many people don't understand right away.
Just because calcium and alk are consumed in a 1:1 ratio, doesn't mean that they naturally exist in seawater in a 1:1 ratio.
Far from it. The concentration of calcium in seawater is proportionally much higher than the concentration of alk.
Each 1 dKH drop in alk only uses up 7 ppm of calcium.
So, for example, if you somehow exhausted all of the alk in a tank starting at 8 dKH, the calcium level would only drop by 56 ppm.
So your alk would then be 0, but the calcium level would be almost unchanged, around 340 if starting at 400 ppm.
This is also why alk levels are generally more volatile than calcium levels; there much less of it in the water to start with.

 

[Daniel91]

@rkpetersen thank you for that detailed run-down.

Just out of curiosity, what would happen if I dosed both elements equal with only paying attention/testing alk and keeping that stable? So in theory I would be blind dosing cal but would just do it based on alk consumption

 

[rkpetersen]

@rkpetersen thank you for that detailed run-down.

Just out of curiosity, what would happen if I dosed both elements equal with only paying attention/testing alk and keeping that stable? So in theory I would be blind dosing cal but would just do it based on alk consumption

You would probably be ok.
However it's a good idea to keep an eye on calcium level, although not necessary to check as often as alk.

 

[roberthu526]

Dosing in equal amount is for when a tank is pretty dialed in with relatively stable consumption on a daily basis.
When you hear people talking about dosing one part more than the other, or just dosing one part but not the other, it’s usually because they have an unbalanced tank with one part being way too high an the other part way too low. To “correct” this situation, people need to dose uneven amount of two part. After the tank water reaches the balanced level of Alk and Calcium, they will start dosing two parts in equal amount.
Most of the time if your tank is fairly stable meaning you have tested regularly and know pretty well about your tank’s consumption, you can just test Alk everyday or every other day and only test calcium weekly. The reason is corals are way more sensitive to Alk swings than to calcium swings. A drop in calcium from 450 to 420 ppm is not a big deal, not ideal but not detrimental. However a drop of Alk from 9 to 8 can cause major issues for many SPS especially Acropora.

 

[ckalupa]

Another thing to remember is that not all systems are made to dose equal or 1:1. Red Sea being one.

 

[jaxredsoxfan]

In my case I have high alkalinity (around 11) and ca around 430. I think it's due to salt - IO red Crystal's. I dose 10ml of bionic all and 12ml of bionic ca daily over 24 hours. I find if I does equal parts the alk stays around 11 but ca will fall lower than the 450 I would like. Mag is around 1370, and i add mag supplement a couple of capful when i do weekly water changes. I suspect if I used a salt closer to "normal" levels I would dose equal parts. I think it just depends on where your tank I'd levels wise and where you want it to be.

 

[rkpetersen]

Here's a chart of 'balanced' calcium and alk levels.
I don't know exactly how this was derived or how valid it is, but it's a starting point.

 

[Hemmdog]

If you blind dose calcium based off alk consumption I can almost guarantee your going to end up 500+ cal very quickly, especially if your talking about a tank that just started a need for dosing at all.

My 90g after a year is now in equal ratio 40ml’s of part 1&2 esv but prior the alk was at least 5ml’s more a day than cal. My 40b I set up in April only has a alk need, I dose it 5ml’s a day, cal drops so slowly i only need to dose it 10ml’s part 2 esv a month.

Magnesium plays a big role in all of this as well and should be kept between 1200-1380 imo.

 

[Randy Holmes-Farley Verified Community Expert]

@rkpetersen thank you for that detailed run-down.

Just out of curiosity, what would happen if I dosed both elements equal with only paying attention/testing alk and keeping that stable? So in theory I would be blind dosing cal but would just do it based on alk consumption

That’s what I recommend, only checking calcium once in a while to make sure it hadn’t drifted too far.

 

[Randy Holmes-Farley Verified Community Expert]

If you blind dose calcium based off alk consumption I can almost guarantee your going to end up 500+ cal very quickly, especially if your talking about a tank that just started a need for dosing at all.

My 90g after a year is now in equal ratio 40ml’s of part 1&2 esv but prior the alk was at least 5ml’s more a day than cal. My 40b I set up in April only has a alk need, I dose it 5ml’s a day, cal drops so slowly i only need to dose it 10ml’s part 2 esv a month.

Magnesium plays a big role in all of this as well and should be kept between 1200-1380 imo.

I don’t agree that calcium will rise all that much, except in scenarios where alk is depleted in other ways, such as a sulfur denitrator.

 

[taricha]

That’s what I recommend, only checking calcium once in a while to make sure it hadn’t drifted too far.

Seconding what Randy said here. I tracked Ca Alk etc daily for 3+ months to calculate consumption rates.
What the Ca data told me was... Exactly the same thing I knew from the Alk consumption, just less accurate measuring Ca. The ratio for calcification is fixed and known. Track Alk as close as you want and that'll tell you how much Ca has been consumed much more accurately than Ca test itself.

 

[infinite0180]

I do what randy says. I dose esv part 1 and 2 equal. I test alk daily or every other day. I check cal once or twice a month and mag once or twice as well. Esv has done a great job so far. Ive just now finally had to dose cal and mag to correct them to where i want. I believe that is because i was using IO salt for weekly water changes and it was slowly bring cal and mag down. I just switched to RS blue salt so that doesnt happen any more...