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

[crsublette]

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!

Very important, which I find many small ma-pa joints often sell old test kits that are quite often inaccurate.

 

[crsublette]

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, it is not the same as the KH test kit.


That is quite likely a TDS meter. TDS is total dissolve solids and it tests exactly as it mentions, that is any dissolved solids in the water. Now, there are particular solids it does not recognize.

TDS meters are often used with reverse osmosis drinking water systems to tell the operator when to switch out filters.

The TDS meter is essentially a test for how well the water was filtered, which is nothing like a KH test kit.


The KH test is test that measures the water's acidic buffer resistance, that is also called alkalinity. If the primary buffer system in the water is carbonate based rather than phosphoric based, then KH is assumed to be a test kit for bicarbonate (HCO3-) due to an acid titration solution or a specialize electrodes (which are quite expensive and definitely not be used in a RO system).

 

[addy1]

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?

I just toss mine into the bog, they do the best where there is a lot of water flow. I tried bagging some, but for my pond it is easier to just toss in un bagged. I don't rinse like Charles says, the dust helps and goes away pretty fast. I add around 100 lbs every spring (big pond), ow our pond water is way too soft.

The 100 lbs is gone by the end of summer.

My pond usually stays in the 100 range with a ph of around 7.8 which to me is great considering our water is around 5.4 out of the well.

Great info Charles

 

[Mmathis]

I just toss mine into the bog, they do the best where there is a lot of water flow. I tried bagging some, but for my pond it is easier to just toss in un bagged. I don't rinse like Charles says, the dust helps and goes away pretty fast. I add around 100 lbs every spring (big pond), ow our pond water is way too soft.

The 100 lbs is gone by the end of summer.

My pond usually stays in the 100 range with a ph of around 7.8 which to me is great considering our water is around 5.4 out of the well.

Great info Charles

I like the idea of putting the oyster shells, loose in the bog! And I don't rinse mine either.

 

[addy1]

They look so white to begin with then just blend in with everything else.

 

[jmajid]

Do not need GH. Do not need phosphate.

Can you give me the reasoning why i dont need the phosphate test?
Its already included in my API master test kit.
Thanks for the explanation on why not to buy the GH test.... i will buy the KH only.

 

[crsublette]

1) Can you give me the reasoning why i dont need the phosphate test?
Its already included in my API master test kit.
2) Thanks for the explanation on why not to buy the GH test.... i will buy the KH only.

1) Can you give me the reasoning why i dont need the phosphate test?

Phosphate test kits we have access to are very unreliable and the test results become skewed after just a minute of the test being done. Even though the box says it tests for total phosphate, this is not true due to the methodology they use for the test. These test kits actually are only testing a very small portion of phosphates that are used by algae or plants, that is orthophosphates, rather than testing the "total active" phosphates, which is what produces more orthophosphates.

I call the phosphate test as one of those "feel good" tests. In the context of a basic freshwater pond hobbyist, it is only used to assume a form of algae control, which is quite silly since it is not this simple.

Seeing a zero or near zero value on the phosphate test makes you "feel good" in that it leads you to believe you may likely not have an algae problem, again which is quite silly.

When the phosphate test has a high value, then leads you to "feel paranoid" due to the chart saying you likely will have an algae problem, again which is quite silly. So, then, the only solution they tell you is to do a major water change or buy another product to absorb the phosphate out of the water, which is not necessary.

To help combat algae problems, then check out the threads: 1) algal blooms ; 2) solving the algae mystery.


2) Thanks for the explanation on why not to buy the GH test.... i will buy the KH only.

You might get a better price if the GH test kit is with it and sometimes the price will come out relatively the same. Right now, at amazon for the KH and GH test kit, the KH only is $5.89 and the KH+GH is $5.99. About a week ago the KH+GH test kit combo was actually cheaper than the KH only test kit. So, this is something to think about.

Also, I should clarify this since some recent reading reminded me of when the GH test kit is actually useful. It has been a long time since I have stopped using the GH test kit for this so I completely forgot about it.

In our context of a freshwater pond hobbyist, GH test kit is mainly "kind of" useful when trying to maintain a healthy bio-filter by adding calcium chloride and epsom salt (that is magnesium sulfate), which the components in these products help to promote good bio-film growth for the microorganisms. This can be read about in the thread, ok, now what do i do. For proper instructions on how to properly dose calcium chloride then read thread "calcium chloride to lower pH" and, to properly dose epsom salt, then read thread proper KH and GH levels. So, to simply state it, it is 16 ounces of calcium chloride per 1,000 gallons and 8 ounces of epsom salt per 1,000 gallons. Dissolve this in their own buckets and then poor around the parameter of the pond. Some folk dose up to 16 ounces of epsom salt, but too much magnesium in the water can cause nutrient deficiencies in plants so I would not go too heavy with this. This is true for the calcium chloride as well since too much calcium can cause potassium nutrient deficiencies in your plants.

So, when you notice the GH test value start to fall below around 200, then dose the water with the two products above.

For me, I only dose the water with these products once in the Fall and once in the Spring and I never needed to use the GH test kit for this.

 

[jmajid]

sorry - no internet yesterday - so no replies
thanks for the info...

 

[Waterbug]

Using oyster shells as a pH buffer is not a good idea imo. They react very slowly so they're a poor buffer. For example say your KH is 70 ppm and you get a thunderstorm that dumps 1" of rain which is in the 2 to 5 pH range. That could drop pond pH in minutes, a pH crash. The oyster shells will eventually bring the pH back up but over hours or days. So the fish experience a crash and a swing.

Crushed oyster shells will bring pH up faster, but still hours so still a crash and a swing. The finer the crush the faster the reaction. If crushed to a fine enough powder the oyster shells will suspend through the water and react almost instantly to maintain pH. Basically what baking soda does. Baking soda, at least the part we care about, is pretty much dissolved oyster shells.

Oyster shells can provide some trace minerals to the water that some people think are helpful. But these are normally already present.

 

[crsublette]

Yep, when push comes to shove and the pond is experiencing potentially harmful pH swings, then I would definitely not rely on any calcium carbonate product, such as oyster shells, as a primary pH buffer. Then, it would be best to properly adjust the KH level with some other faster dissolving bicarbonate or carbonate product, as previously described.

Generally, unless there are other desires involved, the KH should stay very well enough above 125ppm (or 7 dKH / drops) so to ensure a stable pH.

 

[Waterbug]

It's a strange concept to me, which I've read many times, that oyster shells shouldn't be used as a primary pH buffer. It implies, or is stated directly, that oyster shells make a great backup, or is somehow a secondary buffer. What is strange to me is if something else, like baking soda, is used as the primary buffer, then oyster shells do nothing at all. It's not like the laws of physics would suddenly breakdown and the baking soda would suddenly stop being a buffer.

I guess the thinking is if KH level isn't tested or maintained that the oyster shells would kick in...but the pond would probably still experience pH crashes and swings. To me that's not really what I think of as a pH buffer.

It's probably no big deal. I think many fish survive pH crashes and swings for years before dying and I think for many pond keepers that's acceptable. Oyster shells just seem to be a sexy thing many people like to add to their pond and whether or not it acts as a reasonable pH buffer is immaterial. Imagining it's a good pH buffer makes people feel good. Fish aren't that expensive for most pond keepers.

I think the oyster shell thing came from people seeing high end Koi breeders in Japan using oyster shell. The point missed was that they were almost all flow through systems, like taking water from a stream and running it thru a pond. Adding something like baking soda does little good since it is always being washed out of the pond. Slower dissolving crushed oyster shell was cheap, available and helped as long as massive amounts were used.

 

[crsublette]

It's a strange concept to me, which I've read many times, that oyster shells shouldn't be used as a primary pH buffer. It implies, or is stated directly, that oyster shells make a great backup, or is somehow a secondary buffer. What is strange to me is if something else, like baking soda, is used as the primary buffer, then oyster shells do nothing at all. It's not like the laws of physics would suddenly breakdown and the baking soda would suddenly stop being a buffer.

I guess the thinking is if KH level isn't tested or maintained that the oyster shells would kick in...but the pond would probably still experience pH crashes and swings. To me that's not really what I think of as a pH buffer.

It's probably no big deal. I think many fish survive pH crashes and swings for years before dying and I think for many pond keepers that's acceptable. Oyster shells just seem to be a sexy thing many people like to add to their pond and whether or not it acts as a reasonable pH buffer is immaterial. Imagining it's a good pH buffer makes people feel good. Fish aren't that expensive for most pond keepers.

I think the oyster shell thing came from people seeing high end Koi breeders in Japan using oyster shell. The point missed was that they were almost all flow through systems, like taking water from a stream and running it thru a pond. Adding something like baking soda does little good since it is always being washed out of the pond. Slower dissolving crushed oyster shell was cheap, available and helped as long as massive amounts were used.

It appears many things seem strange to you once you stopped studying the subject material, which is quite fine...

It is a fact the maximum solubility of calcium carbonate is around 8.2 at around the 72~75*F temp range, which was referenced on Roark's website, that is before it went offline due to how he got tired of the "know it alls" giving him grief by twisting his words to make him look bad... I PDF archived it... will try to look for it in my digital hobby library. Actually, wikipedia indicates calcium carbonates solubility in very slightly higher pHs, depending on the water's salinity. (http://en.wikipedia.org/wiki/Calcium_carbonate)

Also, there are localized acidic zones created, such as within the bio-film and around plant roots and in bogs, where the calcium carbonate dissolves creating free calcium and bicarbonate, depending on the acid it reacts with.

In the context of its pH buffering capabilities, I would rather take Mr. Russell Peter's word for its effectiveness, in post#10 in American Myth thread, "Baking soda is not great product for Kh, in my opinion, because it raises pH. I use Lithaqua and it lowers my pH to 7.6 from 8.6 and buffers my KH. I have never had any issues." Back then, when it was still available, he used a calcium carbonate product in the form of calcified algae called Lithaqua, which is actually not crushed at all and in quite large granules. After considering the significant quality of koi and monetary volume in fish he maintains from his Japan trips, I will take his word for it. Also, Mr. Peters does not use a significant flow through system due to his desire to avoid water that is too alkaline since his source water is more alkaline than he desires.

So, this attempt you have of fondly shrugging it off so quick is not well founded...

 

[Waterbug]

It is certainly true that some people like to keep their pond at a pH of their choosing. Pick a number. I'd love have stable water at say 6.8. Would be great for my plants. As long as it was butt simple and cheap. And if you wanted to start a thread to debate all the different ways a pond can be buffered to get stable pH at whatever pH level you personally want I think that would be great.

My posts on the other hand, in this thread, have absolutely nothing to do with whether this person or that person likes baking soda or not. My posts were about how well oyster shells worked as a pH buffer.

I personally don't really like baking soda as a buffer, but I do like that it's cheap and easy so I use it. Plus the places I've kept ponds the source water has been hard. I totally get some people do use RO to reduce source water hardiness so they can run a pond at 6.8, 7, 7.5 or whatever they want to get some results they're after. That's more than I'm willing to do for the 6.8 water I'd like.

The acidic zones thing is pretty funny. Kind of obvious. Not really sure it needs such a scary sounding name. Pretty sure a good KH level is the best way to stabilize pH, even in those scary sounding acidic zones of doom. There are many, many ways to get good KH levels. Baking soda is only one. Even oyster shells can create a good KH level depending on many factors. But tossing a big bag of oyster shells into a pond is probably going to disappoint a lot of keepers, at least those who test water and have KH issues (soft source water, high rain area, high fish load with high feeding amount, etc). For many people KH is never an issue even when no buffer is added and then it certainly does no harm to think oyster shells are the reason whether true or not.

 

[crsublette]

It is certainly true that some people like to keep their pond at a pH of their choosing. Pick a number. I'd love have stable water at say 6.8. Would be great for my plants. As long as it was butt simple and cheap. And if you wanted to start a thread to debate all the different ways a pond can be buffered to get stable pH at whatever pH level you personally want I think that would be great.

My posts on the other hand, in this thread, have absolutely nothing to do with whether this person or that person likes baking soda or not. My posts were about how well oyster shells worked as a pH buffer.

I personally don't really like baking soda as a buffer, but I do like that it's cheap and easy so I use it. Plus the places I've kept ponds the source water has been hard. I totally get some people do use RO to reduce source water hardiness so they can run a pond at 6.8, 7, 7.5 or whatever they want to get some results they're after. That's more than I'm willing to do for the 6.8 water I'd like.

The acidic zones thing is pretty funny. Kind of obvious. Not really sure it needs such a scary sounding name. Pretty sure a good KH level is the best way to stabilize pH, even in those scary sounding acidic zones of doom. There are many, many ways to get good KH levels. Baking soda is only one. Even oyster shells can create a good KH level depending on many factors. But tossing a big bag of oyster shells into a pond is probably going to disappoint a lot of keepers, at least those who test water and have KH issues (soft source water, high rain area, high fish load with high feeding amount, etc). For many people KH is never an issue even when no buffer is added and then it certainly does no harm to think oyster shells are the reason whether true or not.

Alas, I think this is going to be the best we are going to do, that is to somewhat come to an agreement. I am actually agreeing with you.


Indeed, as well as I am posting as to "how well oyster shells works as a pH," which was the entire point of sharing Mr. Peter's application of when a calcium carbonate product does work. I was simply pointing out that there are reasonable applications for the product, dependent on the person's water, which indicates as well the opposite where there are situations that the product has little impact that is the reason why I mentioned other products. You entirely missed the point if you thought that this was mentioned so to say "whether this person or that person likes baking soda or not".


Not for sure why "the acidic zone thing" sounds "scary". It is just a fact as to one reason why some folk's ponds have more alkalinity consumption than others and explains where and why it would be a good location for the application of these calcium carbonate products.


Having stable water at a 6.8 pH is actually quite easy. Once the money is spent to reduce the alkalinity through a chemical dilution process of the original with either another water or acid, then a "butt simple and cheap" way to keep a stable water pH at 6.8 is to use a combination of a bicarbonate or carbonate product along with a slow dosage of the more alkaline water, that is dosage is done through a type of DIY'd "medical IV" device or DIY'd venturi mimicking the function as an auto pH dosage system, where the alkaline water is either tap water or a created solution from hydrated lime (calcium hydroxide). It is actually quite simple and cheap.

This idea is not my own.. I have seen this approach used in aquaponic systems so to maintain their pH levels, which is quite volatile since their KH levels are essentially zero or maybe on occasion only 1~2 dKH or drops (around 17~35ppm). The only downside to this system is that, if proper electronic safeguards are not put into place, then the water will have to be attended to on a daily or multiple times a day as a safe guard to ensure the low tech dosage device does not suddenly stop working nor shoot the pH through the roof.

Actually, to obtain organic certification for aquaponic systems, according to the OMRI (http://www.omri.org/omri-lists), hydroxide solutions are not allowed (http://www.omri.org/simple-gml-search/results/calcium hydroxide) so calcium carbonate, such as oyster shells and dolomitic lime and other bicarbonate products are often used. Actually, Friendly Aquaponics, which has been a successful aquaponic system, describes exactly this in their newsletter, Why the Nutrients Disappeared. (http://hosted.verticalresponse.com/527375/4135faed19/1451003007/125667f02a/). Friendly Aquaponic's actually heavily rely on calcium carbonate products, such as oyster shells, as one of their primary pH buffers.

Also, sodium bicarbonate, that is baking soda, is a big "no no" in these systems due to the significant impact of sodium on plants. However, in our pond context, this is not an issue since we do not use anywhere near as high volume as they use in their systems; so, in our pond context, the sodium is less of an issue, except, as described earlier, over time it will increase the water's salinity thus requiring a significant water change once a year or so.


By the way, in Friendly Aquaponic's Hawaii operations, their system is completely exposed to constant heavy rains. The rain actually does not impact their system as much as is thought. Actually, nutrient dilution is much more of a concern to them during heavy rains rather than pH stability, which goes to show how effective they are in their pH stability products.

For anyone curious, aqua-ponics is the collision of two interests that involve growing healthy fish while growing healthy plants, which often many backyard aqua-ponic systems use goldfish and koi. To learn more, then read the thread, "Is aquaponic farming viable?" (https://www.gardenpondforum.com/thr...ing-truly-viable-on-a-commercial-scale.13572/)


Yet, of course, the entire point of me posting here is to show that there are also applications of when calcium carbonate products are less effective, thus the reason why I mention the application of a bicarbonate product such as baking soda or potassium bicarbonate.

So, again, I don't think it is smart to totally knock the effectiveness of calcium carbonate products and, correct, not all calcium carbonate products are created equal, which is why it is much better to use a product that is crushed or pulverized or, yet even better, in powder form as long as it is properly dissolved first so to avoid fish gill irritation. Personally, I prefer the crushed or pulverized version.