Reef nutrition

Alkalinity and Calcium consumption differences…

wazzupmac

Supporting Member
I read an awful lot on as many of these subjects as possible - not like a chemist but I do find it fascinating.

So I recently fired up the 150 gallon tank with a 60 gallon sump (it has about 40 gallon at optimal level). The trident is set up and the Hanna testers are my backup. The calcium has remained fairly constant - I can’t get it to consistently crack 400 but I’m trying to not chase some unicorn numbers. My alk has been as high as 10 but it keeps dropping down towards 9ish. I know 8-12 is the general target.

I dose manually with ESV Bionic 2-part. Usually only once a day because I’m not in my office much. I do have a DOS (3 of them - if someone wants 1, let me know). I should have that setup with the DDR with 2 weeks.

1/2 of the rock added to the tank was live with tons of coralline algae. 1/2 was live but living in a Brute for 6-8 months. No mini cycle or nothing when everything was transferred and set up.

Could rapid coralline growth be accounting for the different rates of consumption? I just added 4-5 frags of SPS too from @dandemeyere. I’ve read conflicting stuff on R2R and the web of what to do though Randy says stick with the 1:1 if that’s what you are doing.

Just want some additional advice and guidance since I trust most of what I’ve read on BAR. Stick to 1:1, adjust alk, etc.?
 

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In my experience, newer tanks will have varying consumption of Alk/CA levels early on. My last tank took about 2 months to finally get to 1:1 Alk/Ca levels, and even then, it would fluctuate once in awhile from day to day. Eventually I just got lazy and didn't check everything daily (manually at the time) and just dosed 1:1. Every week or two I would do another full test, and things would be just fine.
 
Pretty normal. Alk effects so much other stuff then just calcification that it can swing from Ca especially when calcification consumption is low. I’m just dosing Sodium Chloride now because I’m using about .15 dKH a day but almost no Ca. My calcification consumption is low so other usages are governing. When consumption goes up you will get closer to a 1:1 because calcification will be a higher percentage of All usage, evening it out.
 
It is normal.

Note that this imbalance causes an extra hassle : B-ionic and only sell additives as a balanced set.
So if you want just Alk, you have to buy a different brand or DIY it. The brand is one issue, but a big problem is that the concentration may be different.
 
I almost never see 1:1, but I’ve now just started mixing my own and know what is normal ish for my mixture
I mixed my own two part for years, but switched back to B-ionic, and it was noticeable to me. (Anecdotal of course)
The problem was that DIY two part is purely calcium chloride and sodium carbonate.
You then have to dose all the other elements, and the only one you can reasonably test is Magnesium.
If you don't, over a long time those drop, unless you do consistent substantial water changes. I did off and on, but was cheap on the salt also.
I never really ended up with a good strategy, so my water was not the best.
 
Could rapid coralline growth be accounting for the different rates of consumption?
Yes. The basic issue here is that some of the "calcium carbonate" that makes up the skeletons of calcifying animals is really magnesium carbonate, so the alk:calcium ratio being consumed in skeleton formation is greater than a 1:1 ratio. Coralline tends to include more magnesium as a fraction of the skeleton relative to other types of animals. I've spoken with Bob Stark @ ESV about this issue. ESV B-Ionic has some magnesium included in the calcium solution to address this issue, but ESV has to guess at the correct percent of magnesium to include, and that percentage will vary from tank to tank, and even for the same tank over time as different organisms with different Mg:Ca ratios in their skeletons predominate in the overall consumption.
 
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I’ve been testing more consistently at same time day after day and also repeatedly thruout a day and seeing swings of close to 1dkh thru the day. Seems like a lot!!!!

My doser doses the same 15ml every hour thru the day.

Does anyone dose more heavily thru the daytime to even out the alk?
 
Yes. The basic issue here is that some of the "calcium carbonate" that makes up the skeletons of calcifying animals is really magnesium carbonate, so the alk:calcium ratio being consumed in skeleton formation is greater than a 1:1 ratio. Coralline tends to include more magnesium as a fraction of the skeleton relative to other types of animals. I've spoken with Bob Stark @ ESV about this issue. ESV B-Ionic has some magnesium included in the calcium solution to address this issue, but ESV has to guess at the correct percent of magnesium to include, and that percentage will vary from tank to tank, and even for the same tank over time as different organisms with different Mg:Ca ratios in their skeletons predominate in the overall consumption.
Excellent summary- quality info like this is hard to find online sometimes
 
I read an awful lot on as many of these subjects as possible - not like a chemist but I do find it fascinating.

So I recently fired up the 150 gallon tank with a 60 gallon sump (it has about 40 gallon at optimal level). The trident is set up and the Hanna testers are my backup. The calcium has remained fairly constant - I can’t get it to consistently crack 400 but I’m trying to not chase some unicorn numbers. My alk has been as high as 10 but it keeps dropping down towards 9ish. I know 8-12 is the general target.

I dose manually with ESV Bionic 2-part. Usually only once a day because I’m not in my office much. I do have a DOS (3 of them - if someone wants 1, let me know). I should have that setup with the DDR with 2 weeks.

1/2 of the rock added to the tank was live with tons of coralline algae. 1/2 was live but living in a Brute for 6-8 months. No mini cycle or nothing when everything was transferred and set up.

Could rapid coralline growth be accounting for the different rates of consumption? I just added 4-5 frags of SPS too from @dandemeyere. I’ve read conflicting stuff on R2R and the web of what to do though Randy says stick with the 1:1 if that’s what you are doing.

Just want some additional advice and guidance since I trust most of what I’ve read on BAR. Stick to 1:1, adjust alk, etc.?
Regarding target alk level- You will find a lot of conflicting advice out there. It’s true different people recommend specific ranges between 8-12 dKH, but no one recommends keeping your alk anywhere between 8-12 in a tank.

Generally, 7 is normal (reef seawater), and artificially high alk promotes growth but is also riskier to the coral at the extremes. I run target 8.5 and am ok with it 8.0 - 9.0. So for me, dropping down to 9 from 10 would be a good thing. Lots of people with great tanks run higher.

My tank generally consumes more alk than expected relative to Ca, presumably for the reasons mentioned above, so I think that part of it is fine.
 
Pretty normal. Alk effects so much other stuff then just calcification that it can swing from Ca especially when calcification consumption is low. I’m just dosing Sodium Chloride now because I’m using about .15 dKH a day but almost no Ca. My calcification consumption is low so other usages are governing. When consumption goes up you will get closer to a 1:1 because calcification will be a higher percentage of All usage, evening it out.
Sodium chloride?
 
Sodium chloride?
Autocorrect. Sodium Bicarbonate. Oops.

A lot of recipes assume the consumption of alk/ca using avg they got from coral, not pure calcium carbonate, so this should account for mg consumption in a way. That is still a variable though as your corals and the concentrations of elements in your water vary. Would need to go to text to determine if each recipient does take mg into account or if the baseline sample holds true.
I remember the avg. based off acros in the ocean. Think last time I looked into it, B-ionic accounted for Mg. Can’t speak for BRS, but Randy mix states it is based of coral calcification not calcium carbonate.

"Additionally, we may want to account for magnesium that is actually incorporated into the coral skeletons. For this calculation, I have assumed that the amount of magnesium incorporated is about 6.5% of the calcium level (by weight), or about 2.5% of the skeleton by weight. In the course of adding this gallon of both parts of the two part supplement, we added 141 grams of calcium, so we need to add 0.065 x 141 = 9 grams of magnesium to account for this deposition."

I can say I am only dosing alk now as ca/mg are stable (trident test data). New tank with only frags so not a good tank sample, but validates alk can be consumed outside of calcification and aligns with @wazzupmac as his tank is also very new. Not dosed CA in well over a month. Alk dropping every day and I’m not at elevated levels. 7.5 - 8.5.

As you get more coral, I would expect calcification to be the primary use but not the only use/function. A softy tank would likely vary from a SPS. You should validate doser accuracy as well because that could just as easily be the issue and the easiest to actually address.
 
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