Fluval 13.5 @ 2 months: Alkalinity Consumption Question

dhof · Jan 31, 2018

I've graduated to the "2-full-month" club! Yes, I understand that my aquarium is probably "too well stocked" for my 2 month badge..... Here's a pic of the current stock level:

PROBLEM:
For about 3 weeks now I've been trying to get my alkalinity to a target of 8.6 dkh (which is what my new batches of salt mix up after 12-24 hrs). I feel like I'm adding a ton of alkalinity each day, in addition to the Kalk, but I'm still losing the battle every day. I basically can get to 8.6 dkh right after dosing Red Sea Alk, but only for a few hours.... 10-12 hours later it is back to 7.4 or 7.1. I do not notice any sort of precipitation or anything like that.

I am also adding calcium in addition to the Kalk, but it seems like I'm able to keep up/catch up to my Calcium target of 440 pretty easily. My Magnesium already mixes up at 1400 from my salt, so I've only had to add that a few times and it stays steady for a few days. The alkalinity is just getting consumed so much faster than calcium or magnesium

I have Kalwasser @ 2 tsp/gal in my ATO. This seems to be the max concentration for Kalk without messing with Vinegar, but my Alkalinity still drops crazy fast even with the kalk being ATO added. I would guess I'm topping off about a gallon per week of ATO RODI/Kalk mixture. The Kalk is not keeping up with the DT Calcium either, but it seems like it isn't as drastic of a problem as my Alk at the moment. I'm not sure why the Kalk isn't keeping up with my DT demands, but I suspect the nano tank just isn't evaporating enough each day.

Today I just bought a DOS for my Apex to help out since my manual dosing is getting pretty crazy swings and possibly this will help stabilize things due to being able to dose in a more regular pattern. I'm still concerned about the drastic consumption difference between Alk and Calcium, and I guess that's the real reason for my post.

Here's a picture of the past 10 days of my alkalinity. I was aiming for 10 dkh until January 24th when I started aiming for 8.6 dkh (note I am low on alk test kit so I haven't been testing after each alk application but I did confirm my calculations were correct on the dosing of the 24th in hitting the target, these are mostly measurements 10-12 hours after I have dosed alk):

Since January 24th, I would say I'm adding:

10-13mL of Red Sea Alkalinity per day (in addition to Kalk) (performed over 2 or 3 applications)
1 mL of Red Sea Calcium per day (in addition to Kalk)
4mL of Red Sea Magnesium every 3 days.

I've heard you really want to dose all 3 parts in a 1:1:1 ratio, but I can't imagine doing that with how out of whack my alkalinity consumption is at the moment compared to calcium. Does anyone have any insight into whether this is normal, or what might be going on?

boozeman27 · Feb 1, 2018

Randy Holmes-Farley · Feb 1, 2018

Edit: I made a unit error in this post (dKH be meq/l) so it was wrong

dhof · Feb 1, 2018

Randy Holmes-Farley said:
I'm not really seeing a problem, and I'm not seeing evidence of anything being out of whack. You just need more alk if you want alk higher

The products you are adding (if I understand them correctly, Reef Foundation A and B) are not a balanced two part system intended for equal parts dosing. The calcium part is much more potent than the alk part.

Alk always drops faster than calcium, on a percentage basis, even when consumed in the appropriate ratio (18-20 ppm calcium, 0-2 ppm magnesium, for each 2.8 dKH of alkalinity).

10 mL per 100 L of the alk additive rasies alk by 0.36 dKH.
https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-b/

10 mL per 100 L of the calcium additive raises calcium by 20 ppm
https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-b/

That is way, way off of the ratio needed for equal parts dosing. Way more calcium than alk.

-----

Thanks for the reply Randy, very much appreciated.

I do understand that it doesn't need to be 1:1:1 dosing, and your feedback makes me feel better about that. The only place that I read that information is on the BRS website (not anywhere else). Their instructions I think are a bit misleading in this respect ( https://www.bulkreefsupply.com/reef-foundation-b-alk-red-sea.html)

My other stumbling block is just the pure amount of alk my DT is consuming on a daily basis. I'm already dosing using the max 2tsp/gal in kalkwasser via my ATO, and that really doesn't even seem to do anything at all (possibly due to low evaporation of a 12g tank?). On top of that ATO kalkwasser, I'm dosing 6.72mL (which for my 12 gallons is 1.4dkh, reportedly the max increase per Red Sea) TWICE per day, and I really need to dose more alk than this to stop dropping alk. That's what really has me confounded: That I'm dosing max kalkwasser ATO, and then the max (for my tank volume) of Red Sea Alkalinity twice each day, and still not even maintaining my alk. In the meantime, my tank is swinging 1.4 dkh 2 or 3 times per day, and that has me worried.

My issue is that I dose the max increase per day of 1.4 dkh, and by the time I get home from work, I've already lost all that 1.4 dkh gain, so I dose it again to increase 1.4 dkh, and by the time I wake up I've lost that gain too. I think once my DOS comes (tomorrow) I should be able to make up all this loss, but i will be dosing 15-20mL per day to keep up. I'm still a bit concerned that this much alkalinity consumption is not normal for a 12 gallon tank like mine.

Randy Holmes-Farley · Feb 1, 2018

You are right. BRS has inappropriate directions, if the Red Sea web site is correct.

Edit: your calculation looks ok

chipmunkofdoom2 · Feb 1, 2018

+1 to what Randy said. Perhaps your ATO had run recently and there was calcium hydroxide present along with the carbonate supplement you added?

Randy Holmes-Farley · Feb 1, 2018

I posted a new thread in the BRS forum about the directions [emoji3]

Randy Holmes-Farley · Feb 1, 2018

Sometimes people get a lot of abiotic precipitation that leads to a false high demand for calcium and alkalinity. You may not even see it.

If you think the demand seems too high for what is in the tank, I might stop the additions for a bit and see how the alk falls. That’s gives the precipitates a chance to get covered with crud that slows the process.

Randy Holmes-Farley · Feb 1, 2018

I reworked my math due to a unit error. The product is balanced.

Randy Holmes-Farley · Feb 1, 2018

I suspect the unbalanced dosing just hasn’t shown up adequately on the calcium test yet. Let me get back to this tomorrow

dhof · Feb 1, 2018

Randy Holmes-Farley said:
You are right. BRS has inappropriate directions, if the Red Sea web site is correct.

I think you are off in the alk calculation. If 10 mL per 100 L (26 gallons) is 0.36 dKH, then you are dosing 0.5 dKH.

How did you get 1.4 dKH?

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Randy, "10 mL per 100 L (26 gallons) is 0.36 dKH" is not how it is written, it is actually written: "1ml will raise the Alk level of 100 liters (25 gal) by 0.036 meq/l (0.1dKH)" I think you have transposed the meq/l with dkh and are using 10mL instead of 1mL.

I hope I'm just off on my calculations, but I can't see where. Here's where I'm at in my calculation, I appreciate a double check:

Per https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-b/ , "Liquid supplement: 1ml will raise the Alk level of 100 liters (25 gal) by 0.036 meq/l (0.1dKH)"
My DT is about 12 gal (approximately half their example size), so I assume that same mL will double the dKH per ml for my tank. i.e. for my 12g, each ml will raise the dkh by 0.21dKH ((25/12)*.1=0.21).
This is where i get a max dose of 6.72ml (6.72ml * 0.21dKH/ml = 1.4 dKH)

In bullet 2 above, that calculation makes sense (the dkh doubles when the volume is halved), but I feel like maybe that is where I'm going in the wrong direction.....

Thanks,

JoshH · Feb 1, 2018

I might have missed it but what test kit are you using for your alk measurements?

dhof · Feb 2, 2018

chipmunkofdoom2 said:
+1 to what Randy said. Perhaps your ATO had run recently and there was calcium hydroxide present along with the carbonate supplement you added?

JoshH said:
I might have missed it but what test kit are you using for your alk measurements?

I use a Hanna checker for both Alk and Calcium. I use the Red Sea test kit for Mg.

Randy Holmes-Farley · Feb 2, 2018

dhof said:
------
Randy, "10 mL per 100 L (26 gallons) is 0.36 dKH" is not how it is written, it is actually written: "1ml will raise the Alk level of 100 liters (25 gal) by 0.036 meq/l (0.1dKH)" I think you have transposed the meq/l with dkh and are using 10mL instead of 1mL.

I hope I'm just off on my calculations, but I can't see where. Here's where I'm at in my calculation, I appreciate a double check:

Per https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-b/ , "Liquid supplement: 1ml will raise the Alk level of 100 liters (25 gal) by 0.036 meq/l (0.1dKH)"

My DT is about 12 gal (approximately half their example size), so I assume that same mL will double the dKH per ml for my tank. i.e. for my 12g, each ml will raise the dkh by 0.21dKH ((25/12)*.1=0.21).

This is where i get a max dose of 6.72ml (6.72ml * 0.21dKH/ml = 1.4 dKH)

In bullet 2 above, that calculation makes sense (the dkh doubles when the volume is halved), but I feel like maybe that is where I'm going in the wrong direction.....

Thanks,

Sorry, last night I noticed I had transposed dKH and meq/L in the data from Red Sea. I edited out my earlier posts .

Randy Holmes-Farley · Feb 2, 2018

So as I see it there are two potential issues here, the perceived difficulty raising alk, and the apparent imbalance in dosing amounts.

Here are some reasons that folks either need or think they need an unbalanced additive over the time frame you are looking at (fairly short) to the degree you are reporting (this rules out minor effects).

1. Test error. Some people have issues with the Hanna calcium checker due to the way they designed it to be so super sensitive to the background blank. Many people have problems with the Red Sea magnesium kit for reasons I do not understand.

2. Dosing pumps may not be delivering the amount people think they are if it is based on timers for measurement.

3. It takes much longer to come to an accurate measure for calcium dosing due to the imprecision of calcium kits. If asked a different way, are you sure that if you dosed equal parts, that the calcium would have risen too much? How do you know without doing it or carefully calculating it?

4. What salt mix are you using? A salt mix with calcium different from the tank target skews the demand for it when doibg water changes (or starting off high), and can do so more than for alk in some cases, even in a mix with high alk.

5. Limewater adds a bit more calcium than alk relative to the demand, but this effect is a longer term issue.

6. Certain methods deplete alkalinity and not calcium. A sulfur denitrator is a big one and and rising nitrate is a smaller one.

dhof · Feb 3, 2018

Thanks again Randy!.

I think I'll just go back to plain RODI in the ATO, and try the Apex DOS pump for Alk and Calcium for a few weeks. I should have much a better sense of my actual consumption from the DOS pumps than what I've been doing with my manual dosing. If I figure this out, or if it starts to normalize more, I'll post to this thread. I'm going to do a 50% water change tomorrow and install the DOS to get a good start to this experiment.

Randy Holmes-Farley · Feb 3, 2018

dhof said:
Thanks again Randy!.

I think I'll just go back to plain RODI in the ATO, and try the Apex DOS pump for Alk and Calcium for a few weeks. I should have much a better sense of my actual consumption from the DOS pumps than what I've been doing with my manual dosing. If I figure this out, or if it starts to normalize more, I'll post to this thread. I'm going to do a 50% water change tomorrow and install the DOS to get a good start to this experiment.

That sounds good. Less limewater will potentially lead to lower pH and less precipitation (if it is a problem).

dhof · Feb 12, 2018

Randy Holmes-Farley said:
That sounds good. Less limewater will potentially lead to lower pH and less precipitation (if it is a problem).

Just a small update. I installed the Neptune DOS that I ordered, and I finally have alk/cal/magnesium very stable at my targets (testing 2x per day and the measurements are pretty linear and flat around my target values).

This solved the main problem I was having: namely huge alkalinity fluctuations between my manual morning dose and my manual evening dose, and not really able to hit my target for very long (if at all).

Still, alk is being used so much faster than calcium. Some people say the Red Sea Foundation A&B should be dosed at 1:1 ratio, but I'm dosing 12.2mL of Alk/day, but only dosing 5.5mL/day of calcium to keep the measurements constant near my target. I'm dosing about 4 mL of Magnesium every other day and it's staying steady too.

I'll just chock it up to having a fairly new tank, and assume eventually I will achieve some sort of 1:1:1 ratio like people say...

Randy Holmes-Farley · Feb 12, 2018

dhof said:
Just a small update. I installed the Neptune DOS that I ordered, and I finally have alk/cal/magnesium very stable at my targets (testing 2x per day and the measurements are pretty linear and flat around my target values).

This solved the main problem I was having: namely huge alkalinity fluctuations between my manual morning dose and my manual evening dose, and not really able to hit my target for very long (if at all).

Still, alk is being used so much faster than calcium. Some people say the Red Sea Foundation A&B should be dosed at 1:1 ratio, but I'm dosing 12.2mL of Alk/day, but only dosing 5.5mL/day of calcium to keep the measurements constant near my target. I'm dosing about 4 mL of Magnesium every other day and it's staying steady too.

I'll just chock it up to having a fairly new tank, and assume eventually I will achieve some sort of 1:1:1 ratio like people say...

Well, if that ratio was accurate over the long term, then it would likely be driven by water changes. There isn't a way that the actual demand is that skewed. In any case, I'd stick with it as long as you are monitoring both calcium and alkalinity.

Randy Holmes-Farley · Feb 21, 2018

FWIW, I do not know if they recently changed the concentrations or have a typo, but the Red Sea site says Foundation is not balanced for 1:1 dosing:

pasted from a different thread:

Red Sea Foundation elements does not appear to be intended for 1:1 dosing (if you accept the data they give on their web site):

https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-b/
Liquid supplement: 1ml will raise the Alk level of 100 liters (25 gal) by 0.036 meq/l (0.1dKH)

https://www.redseafish.com/reef-care-program/reef_foundation_program/reef-foundation-a/
Liquid supplement: 1ml will raise the Ca level of 100 liters (25 gal) by 2ppm.

So if we add 27.8 ml of each part to 25 gallons, we will have added:

27.8 x 0.036 meq/l = 1.00 meq/L (2.8 dKH)
27.8 x 2 ppm = 55.6 ppm

That is not the ratio for 1:1 dosing. The calcium part is way more potent and that is probably why you are using so much less. For 1:1 that same 27.8 mL per 25 gallons ought to be delivering about 18-20 ppm.