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kH (carbonate hardness or total alkalinity)
As you may know, there are many things that can cause your pH to fluctuate, and most of them will cause the pH to drop. For this reason, it is vital to constantly monitor the pond’s pH. Now you might be wondering what you can do about all of this if you do see diurnal fluctuations in your pH of more than .3 (three tenths).
That brings us to kH, also known as alkalinity, total alkalinity, and/or temporary hardness. Call it what you want, but in water keeping circles it is usually referred to simply as kH, and is the most important parameter to monitor in an outdoor pond. kH is the buffering capacity of your water, and is usually measured in dKH (degrees of harness) or PPM (parts per million). As acids are introduced by the varying methods described above, it is the kH (carbonates) which instantly neutralize them and keep them from making your water more acidic and causing pH changes or crashes. Without the proper kH levels to counteract these pH secretions, your pond is a ticking time bomb, and all of your fish are at risk.
These carbonates/kH are used up each time they neutralize these acids, and it is for this reason that we must monitor their levels. Therefore the kH has to be monitored on a regular basis, and you will have to most likely replenish it at various times throughout the year.
Acceptable kH levels for our ponds would be between 80 and 200 PPM depending on many factors as discussed above. If you have lots of pond plants, algae growth, green water, heavy fish loads, and high feed rates, to name a few, than you should try to maintain the higher end numbers between 150 PPM to 200 PPM. In the average pond maintaining a kH of 150 ppm is usually more than sufficient. With this level of carbonate hardness, you should not see very much change in the daily pH values, and you will be protected from the dreaded "pH crash"! It is possible however, that in times of extreme plant growth in your pond,( algae blooms as well) that the pH can fluctuate more than the three tenths, but as long as you maintain the proper kH levels, the fish will be fine.
Now, let's say you get a kH test kit and it only gives you your kH readings in degrees of hardness. To convert degrees of hardness to PPM, simply multiply by 17.9. For example, if your kit tells you your kH is 5 in degrees of hardness, simply multiply 5 times 17.9 to get the equivalent in PPM. In this case the PPM would be 89.5 PPM, and would fall in the acceptable range we want.
Raising kH
If you test your kH and it falls below the minimum 80 PPM, then you need to raise it gradually. This is done by simply adding sodium bicarbonate (baking soda). But, remember the importance of keeping the fish's environment stable? Well, it is for this reason that you should never raise your kH more than 20 PPM per
24-hour period. For example, if your kH was 40 PPM, you will have to add the baking soda twice over a 48-hour period, with each addition being 24 hours apart, to get it to the minimum 80 PPM.
NOTE: You should recheck your kH reading 24 hours after each addition of baking soda to make sure it is not increasing more than desired due to some sort of miscalculation on your part, such as pond gallonage or baking soda measurement, etc. Also, you must be aware that baking soda has a consistent pH of 8.4, and will raise the pH of your pond to this figure if it is below that. Also, be sure to check your ammonia in your pond before the addition of baking soda. Ammonia becomes much more toxic as the pH rises above the neutral reading of 7,so if you have any ammonia in your pond I would not recommend the addition of the baking soda until you get the ammonia to 0 ppm.
The general rule of thumb for increasing your kH is by 20 PPM increments every 24 hours, by adding ½ cup of baking soda per every 1,000 gallons of pond water. For smaller volumes you would add about 1/4 TEASPOON for every 10 gallons of water to raise the kH 20 PPM. Remember, however, to recheck your kH and pH 24 hours after each addition. It is also wise to keep an eye on your fish for any adverse reactions during this period, but if you have calculated correctly, there should be none. You would have to be off tenfold to really see a negative reaction from the fish.
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As you may know, there are many things that can cause your pH to fluctuate, and most of them will cause the pH to drop. For this reason, it is vital to constantly monitor the pond’s pH. Now you might be wondering what you can do about all of this if you do see diurnal fluctuations in your pH of more than .3 (three tenths).
That brings us to kH, also known as alkalinity, total alkalinity, and/or temporary hardness. Call it what you want, but in water keeping circles it is usually referred to simply as kH, and is the most important parameter to monitor in an outdoor pond. kH is the buffering capacity of your water, and is usually measured in dKH (degrees of harness) or PPM (parts per million). As acids are introduced by the varying methods described above, it is the kH (carbonates) which instantly neutralize them and keep them from making your water more acidic and causing pH changes or crashes. Without the proper kH levels to counteract these pH secretions, your pond is a ticking time bomb, and all of your fish are at risk.
These carbonates/kH are used up each time they neutralize these acids, and it is for this reason that we must monitor their levels. Therefore the kH has to be monitored on a regular basis, and you will have to most likely replenish it at various times throughout the year.
Acceptable kH levels for our ponds would be between 80 and 200 PPM depending on many factors as discussed above. If you have lots of pond plants, algae growth, green water, heavy fish loads, and high feed rates, to name a few, than you should try to maintain the higher end numbers between 150 PPM to 200 PPM. In the average pond maintaining a kH of 150 ppm is usually more than sufficient. With this level of carbonate hardness, you should not see very much change in the daily pH values, and you will be protected from the dreaded "pH crash"! It is possible however, that in times of extreme plant growth in your pond,( algae blooms as well) that the pH can fluctuate more than the three tenths, but as long as you maintain the proper kH levels, the fish will be fine.
Now, let's say you get a kH test kit and it only gives you your kH readings in degrees of hardness. To convert degrees of hardness to PPM, simply multiply by 17.9. For example, if your kit tells you your kH is 5 in degrees of hardness, simply multiply 5 times 17.9 to get the equivalent in PPM. In this case the PPM would be 89.5 PPM, and would fall in the acceptable range we want.
Raising kH
If you test your kH and it falls below the minimum 80 PPM, then you need to raise it gradually. This is done by simply adding sodium bicarbonate (baking soda). But, remember the importance of keeping the fish's environment stable? Well, it is for this reason that you should never raise your kH more than 20 PPM per
24-hour period. For example, if your kH was 40 PPM, you will have to add the baking soda twice over a 48-hour period, with each addition being 24 hours apart, to get it to the minimum 80 PPM.
NOTE: You should recheck your kH reading 24 hours after each addition of baking soda to make sure it is not increasing more than desired due to some sort of miscalculation on your part, such as pond gallonage or baking soda measurement, etc. Also, you must be aware that baking soda has a consistent pH of 8.4, and will raise the pH of your pond to this figure if it is below that. Also, be sure to check your ammonia in your pond before the addition of baking soda. Ammonia becomes much more toxic as the pH rises above the neutral reading of 7,so if you have any ammonia in your pond I would not recommend the addition of the baking soda until you get the ammonia to 0 ppm.
The general rule of thumb for increasing your kH is by 20 PPM increments every 24 hours, by adding ½ cup of baking soda per every 1,000 gallons of pond water. For smaller volumes you would add about 1/4 TEASPOON for every 10 gallons of water to raise the kH 20 PPM. Remember, however, to recheck your kH and pH 24 hours after each addition. It is also wise to keep an eye on your fish for any adverse reactions during this period, but if you have calculated correctly, there should be none. You would have to be off tenfold to really see a negative reaction from the fish.
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