Alexander1312
Supporting Member
I see. Old tank content in a new box. Indeed surprising that you still have high PH. Maybe this stuff soaked in kalk for 20 years....
Alex’s IM 150 EXT
- Thread starter Alexander1312
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Alexander1312
Supporting Member
Some small good news on the PH front is that I re-tested with a Milwaukee MW102 Pro, with its dedicated temp acclimation, freshly dual recalibrated and I got 0.1 higher PH. At least this means the PH does not get too low at night which has been my main concern. Still not good enough. Need to keep working on it.
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Same tank, I just moved it down here, but a lot of stuff sat half the day in buckets or dry.
Alexander1312
Supporting Member
Misread earlier, apologies. Per your journal, the tank now sits in a fresh air like environment with no fish and fish food so there should not be much buffering needed. This is seen in the smaller PH swings on your chart. So not a surprise really to see the PH being like that despite unplugging temporarily kalk and refugium. Creating the same environment as before would have probably seen a different development is my guess.
When I stopped Kalk my PH dropped instantly by 0.2, unplugging the still developing refugium was less impactful other than larger swings at night. So both will have impact in a like for like environment.
Alexander1312
Supporting Member
Impact of bacteria on PH
I feel we have a bit of a narrow view of what impacts PH, still all valid points in theory. Here is my take and my preliminary conclusions as it relates to my PH issues and how to try fixing them:
Excessive bacterial colonies in a reef tank can lead to elevated CO2 levels in the water, even if alkalinity remains normal. This occurs because many bacteria, especially heterotrophic ones, produce CO2 as they break down organic material or metabolize nutrients.
I have dosed excessively PNS Pro Bio in the beginning of this tank. Purple non-sulfur bacteria (PNSB) are heterotrophic.
My CO2 levels inside the water are outside the desirable range even though the ambient air does not go beyond 600 ppm CO2, mostly lower than that. Also, the nano tank which is in the room next door shows relatively normal PH up 8.2 (and was never dosed with PNSB).
Lastly, I am dosing alkalinity excessively to keep dkh up. Approx twice as much commpared to other tanks my size. Since bacteria (and alage and corals) are a key consumer of alkalinity, and I have very little to no visible algae in either the DT or sump, I strongly believe the bacteria taking the excessive amounts that the corals do not get or need.
Therefore, my plan is now to use UV to try to reduce these bacterial colonies. I strongly prefer ozone over UV for 24/7 use, but this is a way of treatment so I can justify using it. However, this will help mainly with free floating bacteria in the water column and not with those on surfaces. I am unsure if basting rocks will help with this process, but I will try that.
Worst case, I will have to start replacing rocks, but this would be more a last resort nad hopefully not needed.
I feel we have a bit of a narrow view of what impacts PH, still all valid points in theory. Here is my take and my preliminary conclusions as it relates to my PH issues and how to try fixing them:
Excessive bacterial colonies in a reef tank can lead to elevated CO2 levels in the water, even if alkalinity remains normal. This occurs because many bacteria, especially heterotrophic ones, produce CO2 as they break down organic material or metabolize nutrients.
I have dosed excessively PNS Pro Bio in the beginning of this tank. Purple non-sulfur bacteria (PNSB) are heterotrophic.
My CO2 levels inside the water are outside the desirable range even though the ambient air does not go beyond 600 ppm CO2, mostly lower than that. Also, the nano tank which is in the room next door shows relatively normal PH up 8.2 (and was never dosed with PNSB).
Lastly, I am dosing alkalinity excessively to keep dkh up. Approx twice as much commpared to other tanks my size. Since bacteria (and alage and corals) are a key consumer of alkalinity, and I have very little to no visible algae in either the DT or sump, I strongly believe the bacteria taking the excessive amounts that the corals do not get or need.
Therefore, my plan is now to use UV to try to reduce these bacterial colonies. I strongly prefer ozone over UV for 24/7 use, but this is a way of treatment so I can justify using it. However, this will help mainly with free floating bacteria in the water column and not with those on surfaces. I am unsure if basting rocks will help with this process, but I will try that.
Worst case, I will have to start replacing rocks, but this would be more a last resort nad hopefully not needed.
RandyC
Supporting Member
"Causation is not correlation" Different tank, different variables. Maybe the gas exchange is better in your nano relative to the volume of water. Maybe there's less bioload (fish/inverts/coral) that produces less co2 than your bigger tank in relation to the size. I wouldn't jump to say it's the bacteria just yet.
Also, a change of 400ppm vs 600ppm in co2 in ambient air is actually a significant delta and not something that should be tossed out as a potential cause of your pH issues. While this graph is of the ocean vs your small tank in comparison, a change of 40-50ppm in co2 in the atmosphere caused a 0.05 pH change in the ocean.
Ocean Acidification Graph
ocean.si.edu
My guess is since you have quite a few fish, some big coral colonies and invertebrates all of which go through respiration producing CO2 at night and you have nothing to counter that in the tank except getting rid of it through gas exchange since you have no fuge, no kalk and no co2 scrubber, your gas exchange may not be as high as you think. I'd again suggest you try on a warmer day and open your windows, turn on your skimmer on the highest setting and open the drain so your cup doesn't overflow and see what happens to pH at night. Better if you can run that way for a couple nights. At one point I thought I was fine in my tank in terms of gas exchange, but a change in skimmer that drew more air in increased my pH by roughly 0.2.
+1, exactly what I have been saying also"Causation is not correlation" Different tank, different variables. Maybe the gas exchange is better in your nano relative to the volume of water. Maybe there's less bioload (fish/inverts/coral) that produces less co2 than your bigger tank in relation to the size. I wouldn't jump to say it's the bacteria just yet.
Also, a change of 400ppm vs 600ppm in co2 in ambient air is actually a significant delta and not something that should be tossed out as a potential cause of your pH issues. While this graph is of the ocean vs your small tank in comparison, a change of 40-50ppm in co2 in the atmosphere caused a 0.05 pH change in the ocean.
View attachment 67075
Ocean Acidification Graph
My guess is since you have quite a few fish, some big coral colonies and invertebrates all of which go through respiration producing CO2 at night and you have nothing to counter that in the tank except getting rid of it through gas exchange since you have no fuge, no kalk and no co2 scrubber, your gas exchange may not be as high as you think. I'd again suggest you try on a warmer day and open your windows, turn on your skimmer on the highest setting and open the drain so your cup doesn't overflow and see what happens to pH at night. Better if you can run that way for a couple nights. At one point I thought I was fine in my tank in terms of gas exchange, but a change in skimmer that drew more air in increased my pH by roughly 0.2.
Two facts to consider:
1. PH is a function of Alkalinity and CO2
2. The CO2 in water will ALWAYS equalize with the CO2 in the air.
Given fact #1: Assuming your Alk is normal, the issue is the CO2 in the water (sounds like you would agree).
Given fact #2: the CO2 in the air is absolutely a significant input to the PH in your tank (and all tanks regardless of their particular biology).
If you are saying you don’t believe the CO2 in the room is a factor, are you saying you don’t believe fact #2? Or are you saying the rate of CO2 production outpaces any amount of aeration you could possibly add?
The former means your tank is some kind of scientific anomaly. The latter would mean your tank would slowly move towards acidity over time. A scary proposition - but more aeration would still be the answer (and/or more time with exposure to 400ppm air).
Alexander1312
Supporting Member
A good question Andy. Mainly peace of mind tbh. When I temporarily did carbon dosing PH went as low as 7.6 (assuming it was 0.1 reading too low, probably more 7.7) at night. These are not healthy numbers, or at least borderline.
Also, when the tank had high PH, you could see corals growing and looking very happy. I do consider PH is the single most interesting parameter to determine tank health (there are others of course), if not masked up by PH enhancing measures. I do not need it to be at 8.4, which I can achieve relatively easily with a scrubber or kalk, but going at 8.2 and not dropping much lower than 8 would be my goal.
Alexander1312
Supporting Member
"Causation is not correlation" Different tank, different variables. Maybe the gas exchange is better in your nano relative to the volume of water. Maybe there's less bioload (fish/inverts/coral) that produces less co2 than your bigger tank in relation to the size. I wouldn't jump to say it's the bacteria just yet.
Also, a change of 400ppm vs 600ppm in co2 in ambient air is actually a significant delta and not something that should be tossed out as a potential cause of your pH issues. While this graph is of the ocean vs your small tank in comparison, a change of 40-50ppm in co2 in the atmosphere caused a 0.05 pH change in the ocean.
View attachment 67075
Ocean Acidification Graph
My guess is since you have quite a few fish, some big coral colonies and invertebrates all of which go through respiration producing CO2 at night and you have nothing to counter that in the tank except getting rid of it through gas exchange since you have no fuge, no kalk and no co2 scrubber, your gas exchange may not be as high as you think. I'd again suggest you try on a warmer day and open your windows, turn on your skimmer on the highest setting and open the drain so your cup doesn't overflow and see what happens to pH at night. Better if you can run that way for a couple nights. At one point I thought I was fine in my tank in terms of gas exchange, but a change in skimmer that drew more air in increased my pH by roughly 0.2.
You are both making very good points, and I do not dispute them.
Main point is that 8.2 PH is possible in a closed room environment despite higher ambient CO2 if alkalinity is properly buffering. If it is not, there is a problem with the buffer. I agree it might not be the bacteria, but I already explored the other options (also, I am no longer sure if it is, after further research, and I had to stop the UV, as per separate thread).
I am running an oversized skimmer for this tank, so I cannot change this, I have four large gyres in the this tank, so I cannot further improve surface agitation and gas exchange overall, and I cannot run an airline to the outside for logistical reasons. Naturally, my PH will not be able to go very high, but again, around 8.2 should be achievable, and limiting the lower amounts so I can continue carbon dosing without worrying about a potential tank crash - @derek_SR your point on moving towards acidity is an actual concern of mine.
Attached my CO2 chart - these values do not justfiy that my PH does not go higher than 8.05.
I am currently working with a couple of folks on an alternative scenario and potential solution, will update this journal if relevant and/or successful.
Still, I appreciate your input on this matter.
RandyC
Supporting Member
Is your surface agitation actually breaking the surface of the water or just "wavy." If it's not breaking the surface, then it's not adding much to gas exchange. Again, I'd recommend turning that skimmer to the highest possible setting and opening the skimmer drain all the way. Even if you have an over sized skimmer, but are running it at the lowest level, it may not be providing as much gas exchange as you think. Actually, now that I mention it, what is your skimmer set to run at?
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RandyC
Supporting Member
Oh, and your point about if alk is buffered correctly there is a max pH that can be achieved, it should be noted that this is possible only if there is an equilibrium of CO2 in the ambient air and in the tank. In the chart below you can see the effect of variable CO2 concentrations in seawater or if it is in equilibrium with a higher CO2 concentration in ambient air.
Chemistry And The Aquarium: The Relationship Between Alkalinity And pH
Randy answers many questions in this complex relationship.
reefs.com
Alexander1312
Supporting Member
The last ICP had 2.78 mmol/L which I believe is similar to meq/L? So I should get 8.2 based on these charts? However, raising alk should improve PH which even if raised to 9 dkh does not impact PH in my case.Oh, and your point about if alk is buffered correctly there is a max pH that can be achieved, it should be noted that this is possible only if there is an equilibrium of CO2 in the ambient air and in the tank. In the chart below you can see the effect of variable CO2 concentrations in seawater or if it is in equilibrium with a higher CO2 concentration in ambient air.
View attachment 67099Chemistry And The Aquarium: The Relationship Between Alkalinity And pH
Randy answers many questions in this complex relationship.
RandyC
Supporting Member
For alkalinity, 1 meq/L = 1 mmol/L.
You can reach a pH of 8.2 only if your co2 concentration in your house is 350-400 ppm and is at equilibrium with your tank. At 6-700ppm of co2 in ambient air, pH max is more like 8-8.1.
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Marine Tank CO2SYS Table
I have shared this many times, but the table is a little easier to read than the graph Randy posted.
2.78 mmol/l = 2.78 meq/l = 7.8dkh
Also I know you prefer carpenters over chemists (
) but this is a good read:
Alexander1312
Supporting Member
I prefer folks who have a reef tank and not just talk about oneMarine Tank CO2SYS Table
docs.google.com
I have shared this many times, but the table is a little easier to read than the graph Randy posted.
2.78 mmol/l = 2.78 meq/l = 7.8dkh
Also I know you prefer carpenters over chemists (
. But thanks for sharing.
Alexander1312
Supporting Member
Taken just now from the same house in two rooms next to each other. One has 579 ppm, the other 580 ppm CO2.
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