Low Kh

[Gordo33]

Kh results with the API test kit : at 3 drops the test water started to turn yellow. With a 4th drop the water became darker yellow. No change in color with a 5th drop. The chart shows for 3-6 drops the Kh is 50 -100 ppm. The Kh is between 50-65 ppm. The pH taken last night and this morning is 7.5 . Other water parameters Ammonia, nitrites,and nitrates were all 0 ppm. Dissolved O2 is between 7-8 ( dont know units) and was tested last night around 8 pm. I do not have a test kit for Gh. Pond has been running 3 plus weeks.

In the 4 years I had the first pond I never tested the Kh and never had issues with pH or fish. I did test the other water parameters in the past and numbers were always good

Do I need to raise the Kh?

 

[Meyer Jordan]

Kh results with the API test kit : at 3 drops the test water started to turn yellow. With a 4th drop the water became darker yellow. No change in color with a 5th drop. The chart shows for 3-6 drops the Kh is 50 -100 ppm. The Kh is between 50-65 ppm. The pH taken last night and this morning is 7.5 . Other water parameters Ammonia, nitrites,and nitrates were all 0 ppm. Dissolved O2 is between 7-8 ( dont know units) and was tested last night around 8 pm. I do not have a test kit for Gh. Pond has been running 3 plus weeks.

In the 4 years I had the first pond I never tested the Kh and never had issues with pH or fish. I did test the other water parameters in the past and numbers were always good

Do I need to raise the Kh?

No. This should be more than sufficient to buffer the pH. To make sure retest the pH, once early (daybreak) in the morning and again at about 3 or 4 PM. There should not be any major fluctuation (more than 1.0). BTW a pH of 7.5 is ideal!
I would recommend acquiring a GH test kit as this is also a very important parameter.

 

[Gordo33]

No. This should be more than sufficient to buffer the pH. To make sure retest the pH, once early (daybreak) in the morning and again at about 3 or 4 PM. There should not be any major fluctuation (more than 1.0). BTW a pH of 7.5 is ideal!
I would recommend acquiring a GH test kit as this is also a very important parameter.

ok thanks , I will retest as recommended and will purchase a GH test kit.

 

[Mitakuye]

@Gordo33 , in biological aquatic systems, carbonate alkalinity concentration efficacy and sufficiency is dependent on its environment and species.

If you are confident in how you built and maintain your aquatic system's "ecosystem", then a 3*dKH (53.694ppm CaCo3) can be sufficient.

Fish are very sensitive creatures, varies across species and small changes in pH and water temperature create notable impacts on fish's biology. Reaction to these impacts are only notable, if not using additional instruments, once biological conditions become observable from behavior to the point of irritation by the fish, which invites potential secondary ailments. In this context, there is much truth to be learned from the wisdom of Benjamin Franklin when he wrote, "an ounce of prevention is worth a pound of cure". In situations like this, as to whether something should be done or not, I often ask myself, "What is the worst that can happen?" If you have unwavering confidence in your answer, then I would not be concerned.

Diurnal pH fluctuations is the best test of visual confidence to know if your your alkalinity concentration is sufficient to maintain a relatively stable pH.

If there is no notable change in fish behavior nor environment at the time of your observance, then the relatively stable pH is sufficiently tolerable for your fish.

 

[Mitakuye]

ok thanks , I will retest as recommended and will purchase a GH test kit.

I think this might be outside the purview of your original question since non-carbonate hardness, referred to as total hardness or general hardness ("GH") is just a specific measurement of particular minerals, dominantly calcium and magnesium. However, if you do experience a pH fluctuation resulting in a pH of 8.3 or higher, then the calcium presence will help to regulate the height of pH. The calcium and other minerals also helps to improve fish's osmoregulatory functions and reduce toxicity of heavy metals to the fish. Typically, this hardness should be in the range of 20~80 mgL CaCO3, closer to the high range, or more preferably double your carbonate hardness. So, if your KH test returns 3*dKH (53.694 ppm CaCO3), then your hardness should be approximately 6*dKH.

 

[Meyer Jordan]

So, if your KH test returns 3*dKH (53.694 ppm CaCO3), then your hardness should be approximately 6*dKH.

Are you saying the GH should be twice KH?

 

[Mitakuye]

Are you saying the GH should be twice KH?

To clarify and tread lightly, if a stable pH is the only concern, then I suggest the concentration of GH and KH should be equivalent. However, as to why I wrote "tread lightly", I am more concerned of good fish growth, thus health, being notably impacted if the GH was in, or lower than, the 20~80 range thus then GH should be twice KH.

To better clarify, my previous statement of "should be in the range of 20~80 mgL CaCO3" must be read as the minimum, rather than a recommendation.

Hope this was clearer than mud.

 

[Meyer Jordan]

I completely agree with the statement that GH and KH should be at equivalent levels, however no reliable source, scientific or commercial, recommends that GH should be more, much less twice, the level of KH.

"It is important to match calcium hardness with total alkalinity concentrations to help stabilize pond pH – this prevents pH from climbing too high."
Alkalinity and Hardness in Production Ponds
World Aquaculture, 33(1): 16-17.
William A. Wurts, Ph.D.

"As a general rule, the most productive waters for fish culture have a hardness and alkalinity of approximately the same magnitude. For example, a water with an alkalinity of 100 mg/l and hardness of 10 mg/l is not as good for fish culture as water in which the alkalinity is 100 mg/l and the hardness is 100 mg/l. Greater production does not result directly from higher levels of hardness and alkalinity per se, but from the higher concentrations of phosphorus and other essential elements that increase along with hardness and alkalinity"
Monitoring alkalinity and hardness
NSW Department of Primary Industries

"Pond water should have adequate levels of alkalinity and hardness for the species under culture, and those levels should not be widely disproportionate"
Managing high pH in freshwater ponds.
Southern Regional Aquaculture Center (SRAC)

 

[Mitakuye]

I completely agree with the statement that GH and KH should be at equivalent levels, however no reliable source, scientific or commercial, recommends that GH should be more, much less twice, the level of KH.

"It is important to match calcium hardness with total alkalinity concentrations to help stabilize pond pH – this prevents pH from climbing too high."
Alkalinity and Hardness in Production Ponds
World Aquaculture, 33(1): 16-17.
William A. Wurts, Ph.D.

"As a general rule, the most productive waters for fish culture have a hardness and alkalinity of approximately the same magnitude. For example, a water with an alkalinity of 100 mg/l and hardness of 10 mg/l is not as good for fish culture as water in which the alkalinity is 100 mg/l and the hardness is 100 mg/l. Greater production does not result directly from higher levels of hardness and alkalinity per se, but from the higher concentrations of phosphorus and other essential elements that increase along with hardness and alkalinity"
Monitoring alkalinity and hardness
NSW Department of Primary Industries

"Pond water should have adequate levels of alkalinity and hardness for the species under culture, and those levels should not be widely disproportionate"
Managing high pH in freshwater ponds.
Southern Regional Aquaculture Center (SRAC)

I read carefully and none of your sources stated that GH should not unequivocally be more than KH, as reviewed below.

Your first source is primarily in context of pH, not health nor growth.

Your second source makes zero connection to this issue other than saying GH and KH should at least be "approximately" equivalent, which is what I wrote, and that an increase production did occur as a result of elements that came along with an increase in hardness.

Your third source did not quantify what is "widely proportionate".

 

[Mitakuye]

@Meyer Jordan , I am not here to argue. You have a disagreement here for a reason I do not understand.

I simply agree to disagree, unless you can provide more substantial references.

 

[Mitakuye]

I completely agree with the statement that GH and KH should be at equivalent levels, however no reliable source, scientific or commercial, recommends that GH should be more, much less twice, the level of KH.

You will struggle finding any reviewed article that specifically disagrees with me since the aquaculture industry lacks resources to do such research, unless the article, as you have referenced, is nuanced for a quite general context.

 

[Mitakuye]

@Meyer Jordan , for whom is this conversation suppose to serve?

 

[Mitakuye]

"As a general rule, the most productive waters for fish culture have a hardness and alkalinity of approximately the same magnitude. For example, a water with an alkalinity of 100 mg/l and hardness of 10 mg/l is not as good for fish culture as water in which the alkalinity is 100 mg/l and the hardness is 100 mg/l. Greater production does not result directly from higher levels of hardness and alkalinity per se, but from the higher concentrations of phosphorus and other essential elements that increase along with hardness and alkalinity"
Monitoring alkalinity and hardness
NSW Department of Primary Industries

Can you provide the hyperlink?

I am quite interested to read if the source quantifies, as well as provide references, for how the other essential elements are added beyond conventional methods of increasing total hardness in the industry.

 

[Mitakuye]

This conversation reminds of how patients would self diagnose, as a result of reading internet articles, prior to talking to their doctor, whom then disagrees with the patient.

 

[Mitakuye]

http://www.dpi.nsw.gov.au/fishing/a...management/monitoring-alkalinity-and-hardness

Ok, I found the reference and is exactly as a I suspected.

The quite brief article does not provide references nor state how the other essential elements are added beyond conventional methods of increasing total hardness in the industry that would be reflected in production from increased hardness. Yet, this is what was provided to dispute me? Quite lazy.