Alkalinity dosing without Calcium

[Randy Holmes-Farley]

It’s a 80 gallon. I am dosing nothing but Seachem reef Carbonate. No water changes for a month. I don’t dose calcium, magnesium at all. Nitrate levels are consistent at 10. If I don’t dose the 2ML daily alkalinity drops.

Ok, so let’s look closely at what that actually means.

2 mL of that product in 80 gallons boosts alk by 0.07 dKH per day. In a week, that’s 0.49 dKH. In three weeks that is only 1.47 dKH.

If you tank consumed alk and calcium in the ratio that is normal, the calcium will drop less than 0.5 ppm per day or 3.3 ppm calcium in a week (definitely not detectable by kit) or 10 ppm in 3 weeks. That 10 ppm is at the margin of detectability with the best of calcium kits.

Thus, I see no reason to think your tank is not performing exactly as expected.

 

[bossman818]

2.5 I’m sorry

Ok, so let’s look closely at what that actually means.

2 mL of that product in 80 gallons boosts alk by 0.07 dKH per day. In a week, that’s 0.49 dKH. In three weeks that is only 1.47 dKH.

If you tank consumed alk and calcium in the ratio that is normal, the calcium will drop less than 0.5 ppm per day or 3.3 ppm calcium in a week (definitely not detectable by kit) or 10 ppm in 3 weeks. That 10 ppm is at the margin of detectability with the best of calcium kits.

Thus, I see no reason to think your tank is not performing exactly as expected.

Ok, so let’s look closely at what that actually means.

2 mL of that product in 80 gallons boosts alk by 0.07 dKH per day. In a week, that’s 0.49 dKH. In three weeks that is only 1.47 dKH.

If you tank consumed alk and calcium in the ratio that is normal, the calcium will drop less than 0.5 ppm per day or 3.3 ppm calcium in a week (definitely not detectable by kit) or 10 ppm in 3 weeks. That 10 ppm is at the margin of detectability with the best of calcium kits.

Thus, I see no reason to think your tank is not performing exactly as

Ok, so let’s look closely at what that actually means.

2 mL of that product in 80 gallons boosts alk by 0.07 dKH per day. In a week, that’s 0.49 dKH. In three weeks that is only 1.47 dKH.

If you tank consumed alk and calcium in the ratio that is normal, the calcium will drop less than 0.5 ppm per day or 3.3 ppm calcium in a week (definitely not detectable by kit) or 10 ppm in 3 weeks. That 10 ppm is at the margin of detectability with the best of calcium kits.

Thus, I see no reason to think your tank is not performing exactly as expected.

Got it! So my tank is doing what it’s supposed to do but In small amounts. Would you dose calcium magnesium in my tank or it’s not needed since levels are undetectable yet?

 

[Randy Holmes-Farley]

2.5 I’m sorry



Got it! So my tank is doing what it’s supposed to do but In small amounts. Would you dose calcium magnesium in my tank or it’s not needed since levels are undetectable yet?

I recommend balanced calcium and alk dosing in any tank. In yours, with low demand, a single product like All fir Reef might be a perfect choice.

 

[Reefahholic]

Well, I believe that folks making such observations are seeing testing issues. I do not believe what you are claiming is real, aside from the effects I noted, and there’s no processes that that I’ve heard of that can explain them.

Next time I see this happen I’ll try to post back here with some data.

Just an obvious question. I understand that corals utilize both when growing, but depending on species, overall chemistry, nutrients, etc., that general relationship obviously differs or deviates moderately or even significantly sometimes away from the norm for whatever reason.

Why should we assume that it always has to be 2.8 alk to 18-20 Ca consumption rate.? You can do a simple search here and see that it happens all the time. I’m sure there are inaccurate test results, but some do appear accurate, and the ICP data I’ve seen is legit. I’ve also seen the flip side of more Cal consumption and less Alk consumption, but is more rare. I think large clams may contribute to this among other animals.


For example here’s a few below:



BALANCING ALK / CALCIUM DOSING

Hey everyone...

I've been puzzled for quite a while on balancing my Alk / Calcium with "2 part dosing". I test 4x a day with trident and occasionally cross check with Hanna / ICPs obviously.

What really puzzles me is that I seem to go through periods where I need to dose an outsized calcium proportion of 2 part, and then other periods where I need to dose a disproportionate amount of Alk. I.e., I'll try putting 30ML on both ALK / Cal on my neptune DOS. Then, my alk starts climbing above 8.5 whereas my Cal is dropping below 400. So then I need to sometimes have my Alk dosing at 15ml whereas clacium is at 45ml for weeks at a time! And vice versa....

So.... I'm just very skeptical that this is due to "testing error" or maligned/uncalibrated dosing pumps. Virtually everywhere I've read say these elements should uptake in exact proportions, and it isn't "scientifically accurate" that this situation should be occurring. I.e.... On R2R, RHF articles, etc. I would like a second opinion here! How is it that I have all but confirmed with ICPs that my tank can go through a period where these elements are consumed disproportionally? Is it a thing, or am I just doing something wrong?

Right now for example, my calcium was sitting at 390 and alk is climbing to 8.5+ (tested with Hanna + trident, awaiting ICP) after dosing 30 ml calcium/day and 10ml alk (ESV B Ionic) for like 2 weeks!

Any thoughts are appreciated, thanks everyone!

—————————————————-

For those using brs 2 part does anyone actually dose in equal amounts? My calcium consumption is way higher than Alk. Dosing 150ml of soda ash and 200 ml of calcium chloride. I though their 2 part solution was supposed to be 1 to 1.

——————————————————

Hello everyone, this is regarding alkalinity consumption.

I’ve read the handbook and searched the group regarding this topic and while I do see that increased alkalinity consumption is normal I wanted to ask the group if anyone else has experienced alk consumption nearly double after only 4 days on the shine?

Thanks!

——————————————————-

 

[Randy Holmes-Farley]

Just an obvious question. I understand that corals utilize both when growing, but depending on species, overall chemistry, nutrients, etc., that general relationship obviously differs or deviates moderately or even significantly sometimes away from the norm for whatever reason.

How could it? They use alk and calcium to form aragonite. They cannot use or store either alone. That has a fixed alk to calcium ratio. The replacement of some of the calcium ions in it with magnesium, strontium, etc, drops the 2,8 dKH /20 ppm calcium to the 18-20 ppm calcium that I typically quote.

 

[Randy Holmes-Farley]

Bear in mind that just a little test error in calcium or salinity can disrupt the expected calcium consumption, and dosers often are not exactly matched in mL/h.

Anyone with rising, falling or rising nitrate will observe different alk impacts, and sulfur denitrator are alk killers.

 

[Reefahholic]

How could it? They use alk and calcium to form aragonite. They cannot use or store either alone. That has a fixed alk to calcium ratio. The replacement of some of the calcium ions in it with magnesium, strontium, etc, drops the 2,8 dKH /20 ppm calcium to the 18-20 ppm calcium that I typically quote.

 

[Reefahholic]

Randy, I agree with you here:

 

[Randy Holmes-Farley]

To answer his question, my ideas are to check the calcium test for accuracy, check the matching of dosers (many folks find they do not match), make sure he didn’t forget to dilute the calcium concentrate, make sure he isn’t doing something that depletes alk (sulfur denitrator, dosing ammonium chloride, etc), to make sure he isn’t adding calcium in an unexpected way (tap water, some additives), make sure the calcium did not come from a salt mix problem, etc.

 

[Randy Holmes-Farley]

As a side note related to something mentioned above, precipitation of calcium carbonate is never a cause of a deviated ratio. If anything, it drives the demand ratio to the ratio I’ve been discussing.

 

[14 foot reef]

I just love threads where people debate Randy's answers. I either am reassured of my findings and knowledge, or I learn new things.
Bravo @Randy Holmes-Farley for always pushing us to learn !!!!!

 

[Lavey29]

Maybe what I am dosing has all and I never noticed. Seachem reef Carbonate? What do you think?

Salinity can change your alk number to if it drops or rises.

 

[Reefahholic]

It kind of seems like you’ve changed your thoughts a little over time. Previously you were more open to the possibility that the rate of consumption may very a lot depending on different circumstances.

I agree that in a perfectly healthy thriving system where things are dialed in, it most
likely will be consumed closer to what you described (2.8 to 18-20).

The AI overview is kinda interesting also and describes the same issues people are seeing. I did realize they’re pulling a lot of their data from us as well as many other websites around the world, and it can’t be trusted, but the response is interesting.

Isn’t the ratio from CaCO3 different than that of NaHCO3? If so that would make more sense why some reefers may see less or more calcium consumption/ demand.

 

[gbroadbridge]

There are still people who believe the earth is flat...

 

[Randy Holmes-Farley]

Let’s not start believing AI misinformation.

At least since 2004 when I wrote the predecessor article to the one above, I have not in the slightest changed my view on calcium and alk consumption rates. In that article I detail the exact reasons and extents of deviations.

When total demand is very low, those minor deviations can be significant or even dominating and do not reflect coral demand. When demand is higher, the demand ratio will be close to the expected ratio, with only water changes and sulfur s having a big enough effect to skew things considerably. Nitrate effects have generally small effects.

 

[Randy Holmes-Farley]

Isn’t the ratio from CaCO3 different than that of NaHCO3? If so that would make more sense why some reefers may see less or more calcium consumption/ demand.

Huh? Sodium bicarbonate is an alk only supplement.

 

[Randy Holmes-Farley]

The statement that corals do not consume alk and calcium at the same rate is absolutely true from a percentage standpoint. There is a lot more calcium in seawater than alk, so alk always declines in a percentage basis far faster than calcium when they are used together.

 

[Reefahholic]

I just love threads where people debate Randy's answers. I either am reassured of my findings and knowledge, or I learn new things.
Bravo @Randy Holmes-Farley for always pushing us to learn !!!!!

I started thinking for myself after Randy told me that Trisodium Phosphate was a “fine choice” for supplemental phosphate dosing. Hehe.

That was not my experience at all. That stuff is horrible IMO. Very poor bioavailability and could not saturate my binding rock. No matter how much I dosed the PO4 level would not come up until I finally switched products. Then… within a week or so I started to get better test results, and the level came up and the tank started to saturate and progress. I’m not saying that it couldn’t be an option for somebody else, but in my case or that particular situation it was a poor choice. Sometimes things are much different in each system, and we cannot always assume that deviation isn’t possible in certain scenarios.

Before (TSP)


After (New product) You can see the green tint on back glass, and dramatic difference in the rock.

So going back to the balanced alkalinity and calcium debate… I just believe that there’s different situations where they’re not gonna be consumed at a 1:1 ratio.

That being said, I have much respect for Randy and he knows that (I do not have a chemist brain), but I do like to challenge anything I hear if I’m not sure of how it works, or why it works the way it does. If the answers I’m getting do not line up or make sense with real life data or my own observations (and others) I have to question why that is. Nothing personal at all. We all have to learn from each other and bounce ideas.

 

[Reefahholic]

The statement that corals do not consume alk and calcium at the same rate is absolutely true from a percentage standpoint. There is a lot more calcium in seawater than alk, so alk always declines in a percentage basis far faster than calcium when they are used together.

So then why is it shocking that Ca would not be balanced or become elevated if they are dosed at a 1:1?

 

[14 foot reef]

I started thinking for myself after Randy told me that Trisodium Phosphate was a “fine choice” for supplemental phosphate dosing. Hehe.

That was not more experience at all. That stuff is horrible IMO. Very poor bioavailability and could not saturate my binding rock. No matter how much I dosed the PO4 level would not come up until I finally switched products. Then… within a week or so I started to get better test results, and the level came up and the tank started to saturate and progress. I’m not saying that it couldn’t be an option for somebody else, but in my case or that particular situation it was a poor choice. Sometimes things are much different in each system, and we cannot always assume that deviation isn’t possible in certain scenarios. So going back to the balanced alkalinity and calcium debate… I just believe that there’s different scenarios where they’re not gonna be consumed at a 1:1 ratio.

Before (TSP)


After (New product) You can see the green tint on back glass, and dramatic difference in the rock.

That being said, I have much respect for Randy and he knows that (I do not have a chemist brain), but I do like to challenge anything I hear if I’m not sure of how it works, or why it works the way it does. If the answers I’m giving do not line up or make sense with real life data or my
own observations (and others)
I have to question why that is. Nothing personal at all. We all have to learn from each other and bounce ideas.

My debate comment was positive and I do enjoy both sides.

His answer was "Fine Choice"