pH & KH -- Questions [and a Good Article]

Mmathis

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I tested my water the other day -- first time for the season. I have my numbers for this test as I write this, but am relying on memory for the results of previous tests (I have the info, just not in-hand at the moment).

Ammonia -- 0
Nitrites & nitrates both -- 0
pH -- 7.8
KH -- 72
GH -- 107

While this pH is a good number, it's slightly lower than usual -- it usually runs around 8-ish, 8.2....

The KH is about the same, maybe a tad lower than past readings, and I know that ideally you want the KH to be above 80, and preferably in the 100's.

About 2 weeks ago I changed out my crushed oyster shells. I keep them in a mesh bag, inside my SKIPPY, where they are in the direct flow of the water.

Should I be concerned at this point, or just continue to monitor? Should I UP the amount of oyster shells? And, if I add baking soda, how much do I add?

BTW, found this article that does a good job of explaining the relationship between pH & KH, and the importance of consistency and making slow, gradual changes....
http://www.jnfkoifarms.com/basicwaterquality/morebasicwaterquality.html
 

crsublette

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I tested my water the other day -- first time for the season. I have my numbers for this test as I write this, but am relying on memory for the results of previous tests (I have the info, just not in-hand at the moment).

Ammonia -- 0
Nitrites & nitrates both -- 0
pH -- 7.8
KH -- 72
GH -- 107

2) While this pH is a good number, it's slightly lower than usual -- it usually runs around 8-ish, 8.2....

The KH is about the same, maybe a tad lower than past readings, and I know that ideally you want the KH to be above 80, and preferably in the 100's.

3) About 2 weeks ago I changed out my crushed oyster shells. I keep them in a mesh bag, inside my SKIPPY, where they are in the direct flow of the water.

4) Should I be concerned at this point, or just continue to monitor? Should I UP the amount of oyster shells? And, if I add baking soda, how much do I add?

1) BTW, found this article that does a good job of explaining the relationship between pH & KH, and the importance of consistency and making slow, gradual changes....
http://www.jnfkoifarms.com/basicwaterquality/morebasicwaterquality.html


4) Should I be concerned at this point, or just continue to monitor? Should I UP the amount of oyster shells? And, if I add baking soda, how much do I add?

Meh, you're on the edge between being concerned or not, that is justifiably right to be paranoid. ;) Personally, I would significantly increase the volume of oyster shells in addition to adding baking soda, which the directions and reasons why are expressed below.

However, for your 3rd question, I would need to know your pond's total volumes of water in gallons and this needs to be an accurate guess, or as close to it as possible.


1) BTW, found this article that does a good job of explaining the relationship between pH & KH, and the importance of consistency and making slow, gradual changes....
http://www.jnfkoifarms.com/basicwaterquality/morebasicwaterquality.html

Yep, Mr. Fornaro does a good job in that article and overall website and is an honest pond consultant. He is also mentioned in another thread, i really wish I had these when i started.

Once the KH is at 7dKH (or 125ppm), then the water's pH will always be at around 8.3~8.5. You can push the KH up to 16 dKH, which is what my source water actually is, and the pH would still be around 8.3~8.5. If the pH is ever higher than this, then this means the water has, in relative relationship to the KH volume, a lower volume of free calcium in the water.


3) About 2 weeks ago I changed out my crushed oyster shells. I keep them in a mesh bag, inside my SKIPPY, where they are in the direct flow of the water.

No reason to change it out since the product is not an absorbent. Now, it might need to be cleaned a little by simply spraying water over it. It is just that, when the pH gets closer to 8.2, then the product's dissolve rate into water significantly decreases and stops dissolving at 8.2 pH. However, again, as the pH drops momentarily, then more of it dissolves. This is why significantly more of the product must be use when a pond's pH is above around 7.3~7.5.


2) While this pH is a good number, it's slightly lower than usual -- it usually runs around 8-ish, 8.2....

Did you test the water earlier in the day than you usually do? Due to your KH being at 72 ppm, then this would explain why the pH is 7.8 rather then around 8.0~8.2ish. This variance is quite likely broader than you realize, that is especially true after a heavy rain storm.

Personally, I would slowly increase the KH to 7dKH (or 125ppm) so there would not be this pH variance throughout the day. The water is dosed slowly by only changing the water KH in 1dKH (or 17.898 ppm) increments over a 24 hour period with typical grocery store, no additives, pure food grade baking soda, that is sodium bicarbonate. The slow dosage is to reduce the stress on the fish since fast changes in alkalinity can make them sick. You can determine the dosage amount from the CNYKOI - Alkalinity (KH) calculator. This product equilibriates, or dissolves, quite fast into water but it is still not instantaneous and takes time to dissolve. Personally, I would first add the predetermined dosage amount, that is dependent on your pond's total gallon volume, to be mixed in a 5 gallon bucket of water and add a small aquarium air stone to this to speed up the equilibriation process; then, after 12 hours, add this solution around the parameter of your pond or in an area of fast moving water such as a stream. Now, after the pond is dosed, wait 24 hours before using the KH test kit to test the water's alkalinity. Then, if you need to increase the KH more, then repeat the aforementioned process.

This could take a period of days to properly adjust, which is quite fine since it takes into consideration the safety of the fish.

However, there is one disadvantage to using pure food grade baking soda, that is sodium bicarbonate, and this disadvantage is the "sodium" component. It takes a long time, that is over a period of a year or so, for this product to increase your pond's salinity quite slightly, that is only 0.05~0.10%. So, if you are heavily relying on this product for alkalinity, then I would do a slow major water change, that is of at least 40%, once or twice a year so to prevent this product from increasing the pond's salinity. Also, this salinity is a different type of salinity when compared to a salinity caused by the accumulation of chloride ions to defend against nitrite poisoning.

This is also why I encourage the use calcium carbonate products even though this product essentially stops dissolving when the pH reaches 8.2 or higher; however, if at any moment the pH were to drop below 8.2, then the product would slowly dissolve into the water. Also, the beneficial bacteria that forms around this product in the water will be given a boost to water filtering as well. There never can be too much of this calcium carbonate product in the pond and I would also strongly encourage using it as a mix, along with laterite clay, in with the pond plant pots and to do a quite heavy layer of it on the bottom of streams and heavy quantities of it in bogs.


Now, instead of baking soda, then you can use Potassium Bicarbonate, which is most often bought online. I could not find any calculator on how to properly determine the dosage volume, but this product is used quite heavily in the aqua-ponic gardening hobby. The aqua-ponic hobby is the result of a collision of interests that involve safely growing fish, even including typical goldfish, and safely growing plants. If this is an interest to you, then check out the thread, is aquaponic farming truly viable?, which I will be doing another update on it here soon.

Potassium Bicarbonate is significantly more expensive than baking soda, but, with this product, you avoid the salinity concerns and also add a nutritional boost to your aquatic plants. Although, there is the potential of this boosting algae growth as well. So, you could go half and half, that is still use baking soda except use less baking soda due to using some Potassium Bicarbonate.

Personally, I would approach the same dosing instructions with Potassium Bicarbonate as I would with baking soda. However, you will have to do a "wait & dose & see" method with Potassium Bicarbonate, in a 5 gallon bucket, so you can determine exactly how much you need so that you do not increase the alkalinity too fast in your pond.

In aquaponics, there is actually a constant flow through drip system that operates much like a medical-IV, that is built much like a venturi, injection into the water to maintain the alkalinity in their systems, which in their systems they try to work with an alkalinity of around 1~2dKH while controlling the pH fluctuations. However, there needs to be multiple safeguards in place with this system to ensure "accidents" do not greatly increase the water's alkalinity too fast.
 
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crsublette

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A quick tip for ya... If you were to do this, that is mix in laterite clay, oyster shells, and pure clay, non-absorbent kitty litter, along with dosing a little of potassium bicarbonate for alkalinity concerns, then this would make your aquatic plants grow incredibly well although along with their evil twin, that is algae, might show up. The laterite would a give your plants a boost in iron, micro-nutrients (trace minerals), and attracts more nitrogen fertilizer from water. The oyster shells will give a boost of calcium and carbonate to the plants and the symbiotic microorganisms helping the plant in the root zone. The pure clay, non-absorbent kitty littery is simply a filler to gain more volume in the pots. The potassium bicarbonate will boost your water's alkalinity and provide a significant volume of potassium to boost the plant's flowering and the potassium will boost your plant's pest resistances, disease resistances, helps plant's root growth by helping the plant more efficiently consume phosphorus, and helps boost plant's osmotic regulatory system; these are some of the main reasons why potassium, that is the K in N-P-K of fertilizer, is one of the three major nutrients for plants.

Iron, as is solved by laterite clay, and potassium, as is solved by potassium bicarbonate and very small portion from fish food, are the two nutrients that are the most deficient in pond water, which is often the reason for poor growth in many terrestrial pond plants and poor flowering, that is most commonly seen in Water Hyacinth.
 
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Mmathis

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Wow, Charles, that's a LOT of information! I do thank you!

Reason I changed out my oyster shells -- after 2 years, there wasn't much left in the mesh bag. Do they dissolve over time? :cautious:

My pond is roughly 3000 gals, but just did some renovation work which made for adjustments in depth & width (slightly deeper and a tad more narrow -- probably canceled each other out). Also, it's not 100% full at the moment (but it WILL be -- a torrential rain just started here!). But go with the 3000. I will eventually re-measure it and use a water gauge next time I fill.

I actually got that pH reading around 3 in the afternoon. Normally I do check it in the morning, though. Will do some AM/PM comparison checks.
 
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What water testing kit is everyone to give such exact readings. Mine just a color that I match up. I don't even have a KH test in the kit.

Charles, your answers are always so detailed! I learn a lot from you.
 
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I should probably add some oyster shells too. My pond is also close to 3000 gal. How much should I add and should it be a fine mesh bag?
Also should you give the O shells a quick rinse off first?? Is it dusty?
 

Mmathis

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What water testing kit is everyone to give such exact readings. Mine just a color that I match up. I don't even have a KH test in the kit.

Charles, your answers are always so detailed! I learn a lot from you.

I use the API liquid kit. I have to buy the KH & GH kit separate.

For the standard tests like ammonia, pH, nitrites, & nitrates, the kit does come with a color-match chart.

But the KH & GH tests are different. For those, it's a titration test, where instead of adding a set number of drops to the tube of pond water, you add the solution a drop at a time, counting the drops until there is a color change. My test kit comes with a conversion table, but you can also just multiply the number of drops by a number to get the result. That number is something like 17.9 or 18.2 -- some odd number with a decimal (I round it to 18).
 
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i too use the API master kit... but i have since found that there are a couple variants of this too...
mine contains the "wide range pH test" and there is another API master test kit that contains both a "low range pH" and "high range pH" test
I dont have a KH or GH test yet - thats on my list... as i am fighting the algae bloom...
 

Mmathis

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i too use the API master kit... but i have since found that there are a couple variants of this too...
mine contains the "wide range pH test" and there is another API master test kit that contains both a "low range pH" and "high range pH" test
I dont have a KH or GH test yet - thats on my list... as i am fighting the algae bloom...
Yes, and that's the one I use, too. It's called the Master Fresh-Water kit. There's one kit by API [think it's called the Master Pond Kit] that includes phosphates, but leaves out one of the other tests. Mine has the low-range/hi-range bottles and I've discovered that I need to use the hi-range one.

Oh, and be sure to note the expiration dates on your kits/bottles! Over time the reagents will not be as accurate. This is probably overkill, but I read somewhere that you should change out your bottles yearly, even if they haven't expired. Not sure I'm going to necessarily recommend doing that, but you DO need to be aware of and watch those dates! I won't buy a kit if I can't read it's exp. date - who knows how long it sat on that shelf!
 
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My Dad tested my water with some sort of meter he uses for his reverse osmosis drinking water system.

It was 900 ppm - is that the same as this KH test?

900 seems super high. I read it should be around 200 - but I don't know if it's the same thing.

I will order the test suggested above.
 

Mmathis

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My Dad tested my water with some sort of meter he uses for his reverse osmosis drinking water system.

It was 900 ppm - is that the same as this KH test?

900 seems super high. I read it should be around 200 - but I don't know if it's the same thing.

I will order the test suggested above.
No clue -- sorry!
 

crsublette

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Wow, Charles, that's a LOT of information! I do thank you!

Reason I changed out my oyster shells -- after 2 years, there wasn't much left in the mesh bag. Do they dissolve over time? :cautious:

My pond is roughly 3000 gals, but just did some renovation work which made for adjustments in depth & width (slightly deeper and a tad more narrow -- probably canceled each other out). Also, it's not 100% full at the moment (but it WILL be -- a torrential rain just started here!). But go with the 3000. I will eventually re-measure it and use a water gauge next time I fill.

I actually got that pH reading around 3 in the afternoon. Normally I do check it in the morning, though. Will do some AM/PM comparison checks.

Quite interesting. I was curious if that was the case, which I bet ya the oyster shells absolutely did dissolve over time into the water. Due to your experience, then it absolutely would be quite beneficial for you to significantly increase the volume of oyster shells in your water, unless you are going to maintain a higher alkalinity with a bicarbonate product. However, if in higher alkaline water, there are localized acidic zones still created where the oyster shell can be beneficial, such as within the microorganisms bio-film and within plant pots.

Also, I bet a portion of the oyster shells were also consumed by the microorganisms as they excrete acidic compounds, which creates a localized acidic zone, causing the oyster shells to dissolve and the microorganisms attracting the residual to be used as an energy source so the microorganisms can perform better.


For a 3000 gallon pond, then you would need 10.02 ounces (or 283.44 grams) of baking soda to increase the KH by 1dKH (or 17.898 ppm).

If you are concerned your pond might be less than 3000 gallons, then you might need to somewhat reduce the dosage amount. When adding these concentrated products, it is quite important to have an accurate estimation of the pond volume, that is within around a 2~5% variance.

First, I would dissolve this amount into a 5 gallon bucket of water, insert a small cheap aquarium diffuser to agitate the water, then after a few hours the baking soda should be thoroughly dissolved into the water. So, now, pour it around the parameter of the pond or in an area of moving water. Now, the baking soda solution needs to equilibriate throughout the pond's water and this takes time, which I usually wait around 24 hours until I test the water's alkalinity again after the dosage.
 

crsublette

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What water testing kit is everyone to give such exact readings. Mine just a color that I match up. I don't even have a KH test in the kit.

Charles, your answers are always so detailed! I learn a lot from you.


API Freshwater Master Test Kit

API Freshwater KH Test Kit


I have found the GH test kit to be quite worthless. At best, it can give you an idea of the calcium concentration in the system, but, since the GH test kit is a test for all divalent ions, that is any mineral with two positive charges, then the test kit becomes quite diluted and even a very weak test for calcium (Ca++) especially if other materials are added to the water, such as Laterite which adds iron (Fe++) to the water, or if your source water is heavy in minerals.

I mentioned calcium since calcium is the divalent cation (Ca++) that helps to prevent the pH from rising above 8.3~8.5 by calcium precipitating with carbonates (CO32-), which creates a non-soluble compound until the pH lowers. In a carbonate buffer system, carbonate is the result of hydroxide (OH-) additions, which is how the pH goes up, and any microorganism or macro-organism (such as fish and any aquatic plant) that releases or consumes inorganic carbons, such as carbon dioxide, contributes to this process. Even the release of acidic compounds, such as carbonic acid that is created from carbon dioxide dissolving into water, impacts the carbonate concentration by creating more carbonate in alkaline solutions, that is when the pH is high. This is one reason why there is less carbon dioxide found in more alkaline water.

Bicarbonates, that is assumed to be tested by the KH test kit above, helps to stop the pH from falling. Calcium, in a carbonate buffer system, helps to stop the pH from rising


Anyways... Short Answer... I don't use the GH test kit...


Although, you might get a better price with the combo packs, that is when GH is with the KH test kit.
 

crsublette

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I should probably add some oyster shells too. My pond is also close to 3000 gal. How much should I add and should it be a fine mesh bag?
Also should you give the O shells a quick rinse off first?? Is it dusty?

Don't rinse it. The oyster shell dust will simply dissolve faster into the water.
 

crsublette

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i too use the API master kit... but i have since found that there are a couple variants of this too...
mine contains the "wide range pH test" and there is another API master test kit that contains both a "low range pH" and "high range pH" test
I dont have a KH or GH test yet - thats on my list... as i am fighting the algae bloom...


Yeah, it is quite aggravating when manafacturers do that with these combo test kits, that is mix matching various tests since often they make up some odd combinations. I think they often do it just so they can remove old inventory out of their warehouse.

The wide range pH test kit is fine except it is not very accurate. I only use the wide range pH test kit to determine if I need to use the low range or the high range pH test kit. The low range or the high range pH test kit will give a more accurate test. You only use the low range pH test kit if the pH is below 7.5, and you only use the high range pH test kit if the pH is above 7.4.

Personally, I think the pH test kit should not be bundled. It should be in its own bundle that only contains the 3 types of pH test kits, that is wide range and low range and high range. Or, if they must have a pH test kit in a bundle, then only have the wide range pH test kit and then sell the low/high range as its own bundle kit.

Or... They could sell a proper bundled test kit that is truly a "master" kit, that only contains the relevant tests, such as all 3 pH test kits, ammonia/ammonium, nitrite, nitrate, and KH.

Do not need GH. Do not need phosphate.
 
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