Alk Consumption too High??

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
Hey everyone,

I need some help here please. I have 160gals in total - 90 display, 40 frag and trigger platinum sump. I regularly was dosing 80-100 ml of alk throughout the day. I went to increase my dose one night about 3 weeks ago and ended up fat fingering the dose to 1000ml instead of 100ml. By the time I saw the trident alert in the am it had dose like 400ml. Luck had it that I received about 8 new acros same day. I did a small water change, cleaned up what I could and let the dkh drop back down.

After that incident it seems like my alk and cal consumption is way too much now. For a while I thought it was from the 16 new frags I have added but in order to keep the Alk around 11 know I am dosing 300ML and 100Ml of calc. I did a major cleanup of sump and tanks yesterday again and continued my dosing. I have tested the water w/ trident and Red Sea kits and the readings are the same. If I don't dose any alk I will drop 2 dkh if not more. Is it possible for that size of a tank to possibly be consuming this much? The supplements are not building up in the sump (have powerhead circulating that area) and the water is not cloudy.

I am using Red Sea foundation and trace colors.

Any insight or suggestions on how to get things back on track?

Thanks so much~!
 
Last edited:
Aquarium Specialty - dry goods & marine livestock

blaxsun

10K Club member
Review score
+0 /0 /-0
View Badges
Joined
Dec 15, 2020
Messages
16,248
Reaction score
19,089
Review score
+0 /0 /-0
Location
The Abyss
I have a 200-gallon system and I dose between 80-100ml of alkalinity daily (mixed reef, mostly LPS but some SPS). The 700-frag system at my LFS consumes about 200ml of alkalinity daily, so I think 300ml is way off (alkalinity is maintained around 8.5dKH in both systems).

I would get a good alkalinity test kit like a Hanna or take a water sample in to get tested. Whenever I suspect my alkalinity is off I dig out my Hanna and recalibrate my Trident based on the numbers.
 
Tidal Gardens

Randy Holmes-Farley

Reef Chemist
Review score
+0 /0 /-0
View Badges
Joined
Sep 5, 2014
Messages
53,475
Reaction score
46,155
Review score
+0 /0 /-0
Location
Arlington, Massachusetts, United States
Keeping alk at 11 dKH does require more each day than keeping it at 7 dKH, and 2 dKH a day is not necessarily excessive for even a soft coral tank with coralline.

Is nitrate rising (that depletes alk)?

Do you see any signs of precipitation, such as hardening sand or seizing pumps?
 
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
@blaxsun - thanks for the reference. Yeah, I did read on another post that after a alk spike or overdose that the readings would not be right. But I also read that if the water is not cloudy the readings should go back to normal. At this point I want to get things back on track while trying to do it in a manner that I dont tick my acros off anymore than they are.
 

mattdg

Well-Known Member
Review score
+0 /0 /-0
View Badges
Joined
Aug 18, 2017
Messages
593
Reaction score
987
Review score
+0 /0 /-0
Location
New Hamburg NY
It is likely precipitation. One option is to continue on with what you were dosing before and let the tank chemistry sort it out, even if it drops. It can be tricky to force your levels back. Better to let it happen gradually. Definitely check your Magnesium. If it is low, so will be your tanks buffering capacity.
 
Tidal Gardens
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
@Randy Holmes-Farley
nitrates are at 6
phos at .03
that is pretty consistent

Only issue I have otherwise is Dino only in frag tank and I believe that is because of the new rack (black egg crate). To try to handle that I have been using microbacter7 and just recently this week razor.

Sand is not hardening from what I can tell. I have add to clean my pump after the overdose but they have been fine as long as I keep a powerhead moving the water where I dose in the sump.
 
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
It is likely precipitation. One option is to continue on with what you were dosing before and let the tank chemistry sort it out, even if it drops. It can be tricky to force your levels back. Better to let it happen gradually. Definitely check your Magnesium. If it is low, so will be your tanks buffering capacity.
Mag is consistent around 1320. I keep running out of alk and cal that's why so spiky.

1649441597470.png
 
Corals.com

mattdg

Well-Known Member
Review score
+0 /0 /-0
View Badges
Joined
Aug 18, 2017
Messages
593
Reaction score
987
Review score
+0 /0 /-0
Location
New Hamburg NY
Randy brings up a good point regarding nitrate. Also, 11 dKH is a high bar to maintain and is a bit dicey for keeping SPS, especially if your nutrients drop. I'm sure you know all this and have a good reason for the elevated level. Anyway, it's beside the point, since you are trying to get back to your base line.
 
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
I am just really getting started with more sps now. I was keeping it around 10ish then got some recommendations from Red Sea to keep it around 12 so was trying to see how that would be. I should prob just dial it back down plus this amount of dosing is more than I care to spend.
 
Reef Chasers Aquaculture
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
I'd still look at a Hanna alkalinity test kit. I love my Trident, but I still need to keep it honest. I'm not saying that your daily alkalinity requirements didn't triple with the addition of 8 small frags - just that it's unlikely.
Yeah, I calibrate it ofter and check it against Red Sea kit. I know ppl love the hanna. I may grab one to check it out. I think a lot of it had to do with increasing the overall alk .. since I had over dosed it I figured I would try that range out.
 

blaxsun

10K Club member
Review score
+0 /0 /-0
View Badges
Joined
Dec 15, 2020
Messages
16,248
Reaction score
19,089
Review score
+0 /0 /-0
Location
The Abyss
I am just really getting started with more sps now. I was keeping it around 10ish then got some recommendations from Red Sea to keep it around 12 so was trying to see how that would be. I should prob just dial it back down plus this amount of dosing is more than I care to spend.
I guess it all depends on what salt you use. The Red Sea Coral Pro is upwards of 10dKH from what I remember.
 
OP
R33f_Hacker

R33f_Hacker

Community Member
Review score
+0 /0 /-0
View Badges
Joined
Jan 29, 2021
Messages
59
Reaction score
42
Review score
+0 /0 /-0
Location
ATL
fritz pro high alk which I really like ... specs from their site

Salinity 35 ppt
Calcium 400-450 ppm
Magnesium 1300-1400 ppm
Alkalinity 10 - 11.5dkh
Strontium 9 ppm
Potassium 400 ppm
 
Tidal Gardens

Randy Holmes-Farley

Reef Chemist
Review score
+0 /0 /-0
View Badges
Joined
Sep 5, 2014
Messages
53,475
Reaction score
46,155
Review score
+0 /0 /-0
Location
Arlington, Massachusetts, United States
I discuss the relative merits of high and low alk below. I would not take salt mix specs as a recommendation for what are optimal levels.


Alkalinity

Like calcium, many corals also use "alkalinity" to form their skeletons, which are composed primarily of calcium carbonate. It is generally believed that corals take up bicarbonate, convert it into carbonate, and then use that carbonate to form calcium carbonate skeletons. That conversion process is shown as:

HCO3- → CO3-- + H+

Bicarbonate → Carbonate + proton (which is released from the coral)

To ensure that corals have an adequate supply of bicarbonate for calcification, aquarists could just measure bicarbonate directly. Designing a test kit for bicarbonate, however, is somewhat more complicated than for alkalinity. Consequently, the use of alkalinity as a surrogate measure for bicarbonate is deeply entrenched in the reef aquarium hobby.

So, what is alkalinity? Alkalinity in a marine aquarium is simply a measure of the amount of acid (H+) required to reduce the pH to about 4.5, where all bicarbonate is converted into carbonic acid as follows:

HCO3- + H+ → H2CO3

The amount of acid needed is equal to the amount of bicarbonate present, so when performing an alkalinity titration with a test kit, you are counting the number of bicarbonate ions present. It is not, however, quite that simple since some other ions also take up acid during the titration. Both borate and carbonate also contribute to the measurement of alkalinity, but the bicarbonate dominates these other ions since they are generally lower in concentration than bicarbonate. So knowing the total alkalinity is akin to, but not exactly the same as, knowing how much bicarbonate is available to corals. In any case, total alkalinity is the standard that aquarists use for this purpose.

Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in some corals. Uptake of bicarbonate can consequently become rate limiting in many corals. This may be partly due to the fact that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration, which is effectively about 5 times higher).

For these reasons, alkalinity maintenance is a critical aspect of coral reef aquarium husbandry. In the absence of supplementation, alkalinity will rapidly drop as corals use up much of what is present in seawater. Water changes are not usually sufficient to maintain alkalinity unless there is very little calcification taking place. Most reef aquarists try to maintain alkalinity at levels at or slightly above those of normal seawater, although exactly what levels different aquarists target depends a bit on the goals of their aquaria.

Interestingly, because some corals may calcify faster at higher alkalinity levels, and because the abiotic (nonbiological) precipitation of calcium carbonate on heaters and pumps also rises as alkalinity rises, the demand for alkalinity (and calcium) rises as the alkalinity rises. So an aquarist generally must dose more calcium and alkalinity EVERY DAY to maintain a higher alkalinity (say, 11 dKH) than to maintain 7 dKH. It is not just a one-time boost that is needed to make up that difference. In fact, calcification gets so slow as the alkalinity drops below 6 dKH that reef aquaria rarely get much below that point, even with no dosing: natural calcification has nearly stopped at that level.

In general, I suggest that aquarists maintain alkalinity between about 7-11 dKH (2.5 and 4 meq/L; 125-200 ppm CaCO3 equivalents). Many aquarists growing SPS corals and using Ultra Low Nutrient Systems (ULNS) have found that the corals suffer from burnt tips if the alkalinity is too high or changes too much. It is not at all clear why this is the case, but such aquaria are better served by alkalinity in the 7-8 dKH range.
As mentioned above, alkalinity levels above those in natural seawater increase the abiotic precipitation of calcium carbonate on warm objects such as heaters and pump impellers, or sometimes even in sand beds. This precipitation not only wastes calcium and alkalinity that aquarists are carefully adding, but it also increases equipment maintenance requirements and can damage a sand bed, hardening it into a chunk of limestone. When elevated alkalinity is driving this precipitation, it can also depress the calcium level. An excessively high alkalinity level can therefore create undesirable consequences.

I suggest that aquarists use a balanced calcium and alkalinity additive system of some sort for routine maintenance. The most popular of these balanced methods include limewater (kalkwasser), calcium carbonate/carbon dioxide reactors, and the two-part/three part additive systems.

For rapid alkalinity corrections, aquarists can simply use baking soda (sodium bicarbonate) or washing soda (sodium carbonate; baked baking soda) to good effect. The latter raises pH as well as alkalinity while the former has a very small pH lowering effect. Mixtures can also be used, and are what many hobby chemical supply companies sell as “buffersâ€. Most often, sodium carbonate is preferred, however, since most tanks can be helped by a pH boost.
 

Is there such a thing as an "easy" acro?

  • YES (tell us about it in the thread)

    Votes: 99 44.2%
  • NO

    Votes: 50 22.3%
  • Not sure

    Votes: 72 32.1%
  • Other (please explain)

    Votes: 3 1.3%
NooPsyche CORAL LIGHT
Top