Hi
Advice required please.
I have high PH in the afternoon of 9, in the morning it is around 8.2 to 8.4
KH is low, I have very soft tap water (3 drops API test - 53.7 ppm), and was advised to put in Kusuri Bio Balance to bring the KH up. I have been doing this for over 10 days and today the KH has gone up slightly but it seems to be bringing the PH up as well.
Was also told to put Lithaqua in filters and trickle tower to buffer PH. Have done this but it is still swinging during the day.
Water tests are Nitrite 0 - Ammonia 0 - Nitrate 0 (use Kusuri tablet tests) - KH (use API Test ) has been 3 to 4 drops (53.7 - 71.6 ppm) this a.m was 5 drops (89.5 ppm) Temp is 19 C. Have been doing small water changes (3000g pond, 100g changed daily)
Can anyone advise how to get the PH lower and stable, the Bio Balance seems to be raising the PH.
In the past I have always run at PH 8.0 but for some reason it has risen to these levels . - Have renewed activate carbon on incoming water supply purifier (6kg container) and 5 micron pre filter cartridge recently.
Fish seem O.K. but don't want to get into a situation where they are not and the PH is unstable.
3000 gallon pond gravity fed, 3 x 33 inch vortexes, (brushes, moving K1, jap matting), 55 watt UV, 4 tier trickle tower with foam, ceramic, bakki balls - lithaqua in jap matting and two tiers of tower, large air supply to pond and filters.
Thanks in advance
PH High KH Low
Moderators: B.Scott, vippymini, Gazza, Manky Sanke
Re: PH High KH Low
Hi Susan, I had a similar issue with high pH readings earlier this season and mine turned out to be the effect of the sun on the pond. ** Skip to the bottom line of this post if you want the short version of what the next two paragraphs will go on to conclude. It'll save you 5 minutes you'll never get back 
**
Like you, my pond had been stable (so I thought) at 7.5 for as long as I could remember until late one afternoon I was baffled and concerned by a reading approaching 9 and rising! This reading coincided with a couple of things I'd done, one of which was installing a new Hanna Instruments pH and temperature meter as I was never wholly convinced that the drop test kit I was using was giving me the accurate readings I was after. The other was that I had inadvertently added some limestone chips (I hadn't realised that they were limestone) on top of some aquatic plant baskets I was putting into the pond to stop the fish digging around in them. As soon as I noticed the dramatic rise in pH I whipped out the baskets and removed every last chip of limestone only to find that it had minimal effect on the readings. I re-calibrated my new meter suspecting that might be at fault - to no avail. Eventually I reached out to the guys on the forum here and Manky Sanke steered me to his article on pH and why it's normal to get variations in pH readings depending on the time of day (http://www.mankysanke.co.uk/html/questi ... ed.html#pH).
Manky will be able to advise you better than me on the wisdom of using Lithaqua as a buffer, I know he recommends Sodium Bicarbonate as a cheap and highly effective method of controlling pH variations and he has a superb (and "fruity") way of explaining the chemical process by which it does this. However, the the action that had the biggest (and fastest) effect on controlling my high pH issue was the purchase of a big 3.5m diameter parasol for £50 off Ebay (similar to the ones they sell in B&Q for almost double the price)! Giving the pond some decent shade dramatically reduced the wild fluctuations in pH I was was getting to something nearer a tolerable level for the fish - I'm not saying it stopped the problem entirely but it's not giving me sleepless nights anymore. I have the "brolly" up pretty much all the time now and have it tethered with bungees to stop it being whisked off into the wide blue yonder when the wind gets up! It's not attractive and I'd rather not have it but it does the job until I can something more permanent and aesthetically pleasing sorted. Obviously changing the water is the other method by which you can quickly regain some control. I did this in combination with the brolly and the addition of sodium bicarb, doing daily water changes of around 10 - 15% for a week or more to get the levels to stabilise around 8.0 to 8.5 (from a range of <7 at dawn to >9 in the late pm at the beginning)! That was a few months ago now and I've been vigilant with keeping the KH up between 6 and 7 which has held the pH at an average around 8.4 give or take. We've had it rain in bucket loads up North late last week and earlier this week which has led to some further dilution and a reduction in pH below 8 for the first time in an age. I'm monitoring carefully to see where it goes from here but I'll let it settle naturally if I can.
So, to conclude.......
...**If your pond is uncovered, it might be worth taking the effect of photosynthesis into account and do a series of small, regular water changes to dilute to a tolerable/controllable range**
Hope this helps and apologies for the long-winded post if you managed to battle your way through it. Regards M
**Like you, my pond had been stable (so I thought) at 7.5 for as long as I could remember until late one afternoon I was baffled and concerned by a reading approaching 9 and rising! This reading coincided with a couple of things I'd done, one of which was installing a new Hanna Instruments pH and temperature meter as I was never wholly convinced that the drop test kit I was using was giving me the accurate readings I was after. The other was that I had inadvertently added some limestone chips (I hadn't realised that they were limestone) on top of some aquatic plant baskets I was putting into the pond to stop the fish digging around in them. As soon as I noticed the dramatic rise in pH I whipped out the baskets and removed every last chip of limestone only to find that it had minimal effect on the readings. I re-calibrated my new meter suspecting that might be at fault - to no avail. Eventually I reached out to the guys on the forum here and Manky Sanke steered me to his article on pH and why it's normal to get variations in pH readings depending on the time of day (http://www.mankysanke.co.uk/html/questi ... ed.html#pH).
Manky will be able to advise you better than me on the wisdom of using Lithaqua as a buffer, I know he recommends Sodium Bicarbonate as a cheap and highly effective method of controlling pH variations and he has a superb (and "fruity") way of explaining the chemical process by which it does this. However, the the action that had the biggest (and fastest) effect on controlling my high pH issue was the purchase of a big 3.5m diameter parasol for £50 off Ebay (similar to the ones they sell in B&Q for almost double the price)! Giving the pond some decent shade dramatically reduced the wild fluctuations in pH I was was getting to something nearer a tolerable level for the fish - I'm not saying it stopped the problem entirely but it's not giving me sleepless nights anymore. I have the "brolly" up pretty much all the time now and have it tethered with bungees to stop it being whisked off into the wide blue yonder when the wind gets up! It's not attractive and I'd rather not have it but it does the job until I can something more permanent and aesthetically pleasing sorted. Obviously changing the water is the other method by which you can quickly regain some control. I did this in combination with the brolly and the addition of sodium bicarb, doing daily water changes of around 10 - 15% for a week or more to get the levels to stabilise around 8.0 to 8.5 (from a range of <7 at dawn to >9 in the late pm at the beginning)! That was a few months ago now and I've been vigilant with keeping the KH up between 6 and 7 which has held the pH at an average around 8.4 give or take. We've had it rain in bucket loads up North late last week and earlier this week which has led to some further dilution and a reduction in pH below 8 for the first time in an age. I'm monitoring carefully to see where it goes from here but I'll let it settle naturally if I can.
So, to conclude.......
...**If your pond is uncovered, it might be worth taking the effect of photosynthesis into account and do a series of small, regular water changes to dilute to a tolerable/controllable range**
Hope this helps and apologies for the long-winded post if you managed to battle your way through it. Regards M
-
Dave Collins
- Nurse Shark
- Posts: 90
- Joined: Sun Aug 05, 2007 10:48 am
- Location: Nr Strasbourg, France
Re: PH High KH Low
Sodium Bicarbonate is the best way of controlling the pH, try keeping the KH at 6 - 8dH add see what happens.
-
Manky Sanke
- Site Admin
- Posts: 554
- Joined: Sun Apr 16, 2006 10:24 am
Re: PH High KH Low
You've had two good answers already but you don't appear to have been given the best information by the person who originally advised you. I'm guessing that you were told that pH variations can be limited by increasing the KH. This is correct but increasing the KH with proprietary products or compounds that contain calcium carbonate also raises the pH towards a value in the region of pH 10 to 11. Raising it with sodium bicarbonate will also raise the pH but only towards a value of 8.4. If your pH happens to be higher than 8.4 because of something you've already added then sodium bicarbonate will actually help reduce it towards 8.4.
If you'll excuse the copy and paste to save me typing it all again, below is what I've previously written in answer to some posts on here about variations in pH that may help you understand a little better:
"It's pretty clear that photosynthesis is causing the pH variations and a varying pH is a cause of stress in koi.
Photosynthesis by algae or blanket weed doesn't affect pH directly. What happens is that, in the presence of light, plants, algae or cyanobacteria absorb carbon dioxide from the water to make the sugars and starches that they need in order to grow.
When carbon dioxide from fish respiration is dissolved in water, it forms carbonic acid. By absorbing dissolved CO2, the plant or algae is removing an acid from the water. That makes water more alkaline which is the same as raising the pH and the mechanism works like this:
Carbon dioxide dissolved in water forms carbonic acid which causes a weak downward force on the pH. With a low KH there will be very little buffering against pH variations and so any changes in downward force on the pH due to greater or lesser amount of dissolved CO2 when the KH is low will cause a greater variation than would happen with a higher KH.
When there isn’t any light, plants etc stop removing CO2 and switch back to normal aerobic respiration which means that they take in O2 and give off CO2. This increased output of CO2 that is released into water dissolves and makes more carbonic acid which, as just described, has a downward effect on the pH.
That's why pH varies more when the pond is exposed to light than it does when it is shaded. There is an increase in dissolved CO2, which lowers the pH, during the night followed by a reduction in CO2 which raises the pH again when it is light. The brighter the light, the more photosynthesis that occurs and the variations in dissolved CO2 become greater. By increasing the KH, what you are doing is increasing the ability of the pond water to resist variations in pH caused by dissolved CO2.
There are a few ways to decrease or remove these variations:
Remove all trace of algae and blanket weed which is easier said than done and I presume you have done all you can in that area.
Increase the KH which, as you've already seen, will damp down the variations but will also tend to take the pH towards 8.4.
Reduce the level of dissolved CO2.
You can decrease the amount of dissolved CO2 by increasing aeration. O2 saturation isn't quite the same as gassing off an unwanted gas such as CO2 in this case. You need good aeration in order to get O2 levels near to saturation and the fact that you're aerating water to that degree will also gas off CO2. That much is true. It's also true that a dissolved gas will make a slight reduction in the actual maximum amount of O2 that can dissolve although you might not be able to measure the slight difference.
So the extra aeration won't noticeably increase your O2 value but it will help drive out CO2.
One way to look at photosynthesis is to consider that doesn't cause pH variations, it restores your pH to it's normal value. That may seem odd but this might make pH variations easier to understand:
Measure your pH at the end a sunny day when photosynthesis has removed as much of the dissolved CO2 as possible and call that your natural pH. Measure it again as early as possible in the morning and the difference between the two is caused by dissolved CO2 due to fish respiration. If you want to reduce this variation, first try greatly increasing aeration to gas off the CO2 and, if that doesn't reduce it enough, you will have to increase the KH with a possible increase in pH.
If there were no fish in the pond there would be no downward night time change, due to dissolved CO2, for photosynthesis to restore or, if you suddenly added a load of fish without altering the aeration, the reduction due to the increase in dissolved CO2 would be greater. So photosynthesis then can be seen as helping to restore the natural pH by removing the variable parameter (dissolved CO2) that lowers it rather than photosynthesis causing an upward variation."
If you'll excuse the copy and paste to save me typing it all again, below is what I've previously written in answer to some posts on here about variations in pH that may help you understand a little better:
"It's pretty clear that photosynthesis is causing the pH variations and a varying pH is a cause of stress in koi.
Photosynthesis by algae or blanket weed doesn't affect pH directly. What happens is that, in the presence of light, plants, algae or cyanobacteria absorb carbon dioxide from the water to make the sugars and starches that they need in order to grow.
When carbon dioxide from fish respiration is dissolved in water, it forms carbonic acid. By absorbing dissolved CO2, the plant or algae is removing an acid from the water. That makes water more alkaline which is the same as raising the pH and the mechanism works like this:
Carbon dioxide dissolved in water forms carbonic acid which causes a weak downward force on the pH. With a low KH there will be very little buffering against pH variations and so any changes in downward force on the pH due to greater or lesser amount of dissolved CO2 when the KH is low will cause a greater variation than would happen with a higher KH.
When there isn’t any light, plants etc stop removing CO2 and switch back to normal aerobic respiration which means that they take in O2 and give off CO2. This increased output of CO2 that is released into water dissolves and makes more carbonic acid which, as just described, has a downward effect on the pH.
That's why pH varies more when the pond is exposed to light than it does when it is shaded. There is an increase in dissolved CO2, which lowers the pH, during the night followed by a reduction in CO2 which raises the pH again when it is light. The brighter the light, the more photosynthesis that occurs and the variations in dissolved CO2 become greater. By increasing the KH, what you are doing is increasing the ability of the pond water to resist variations in pH caused by dissolved CO2.
There are a few ways to decrease or remove these variations:
Remove all trace of algae and blanket weed which is easier said than done and I presume you have done all you can in that area.
Increase the KH which, as you've already seen, will damp down the variations but will also tend to take the pH towards 8.4.
Reduce the level of dissolved CO2.
You can decrease the amount of dissolved CO2 by increasing aeration. O2 saturation isn't quite the same as gassing off an unwanted gas such as CO2 in this case. You need good aeration in order to get O2 levels near to saturation and the fact that you're aerating water to that degree will also gas off CO2. That much is true. It's also true that a dissolved gas will make a slight reduction in the actual maximum amount of O2 that can dissolve although you might not be able to measure the slight difference.
So the extra aeration won't noticeably increase your O2 value but it will help drive out CO2.
One way to look at photosynthesis is to consider that doesn't cause pH variations, it restores your pH to it's normal value. That may seem odd but this might make pH variations easier to understand:
Measure your pH at the end a sunny day when photosynthesis has removed as much of the dissolved CO2 as possible and call that your natural pH. Measure it again as early as possible in the morning and the difference between the two is caused by dissolved CO2 due to fish respiration. If you want to reduce this variation, first try greatly increasing aeration to gas off the CO2 and, if that doesn't reduce it enough, you will have to increase the KH with a possible increase in pH.
If there were no fish in the pond there would be no downward night time change, due to dissolved CO2, for photosynthesis to restore or, if you suddenly added a load of fish without altering the aeration, the reduction due to the increase in dissolved CO2 would be greater. So photosynthesis then can be seen as helping to restore the natural pH by removing the variable parameter (dissolved CO2) that lowers it rather than photosynthesis causing an upward variation."
Re: PH High KH Low
Many thanks to you all for the detailed replies - this forum is a great resource to all Koi keepers.
Thought I had come across most of the problems during the past 26 years of Koi keeping but this one had me confused (or am I just getting old).
Just to be sure that I am understanding and before I move forward the things I am about to do are :-
1. Add shade to the pond by covering pergola - it is in full sun (when it shines) from mid day to about 5 in the afternoon (no plants in pond).
2. Add sodium bicarbonate in the quantity of 70 grams per 500 gallons (3000 galls = 420 grams) to stabilise the PH at 8.4 and increase the KH(at 4 pm this afternoon PH reading 9.0, tap water 8.4 ).
3. Leave all other items as previously described.
If I don't hear otherwise I will assume you concur.
Many thanks again.
Susan
Thought I had come across most of the problems during the past 26 years of Koi keeping but this one had me confused (or am I just getting old).
Just to be sure that I am understanding and before I move forward the things I am about to do are :-
1. Add shade to the pond by covering pergola - it is in full sun (when it shines) from mid day to about 5 in the afternoon (no plants in pond).
2. Add sodium bicarbonate in the quantity of 70 grams per 500 gallons (3000 galls = 420 grams) to stabilise the PH at 8.4 and increase the KH(at 4 pm this afternoon PH reading 9.0, tap water 8.4 ).
3. Leave all other items as previously described.
If I don't hear otherwise I will assume you concur.
Many thanks again.
Susan
-
Manky Sanke
- Site Admin
- Posts: 554
- Joined: Sun Apr 16, 2006 10:24 am
Re: PH High KH Low
Susan,
Koi can suffer from hardness shock if the KH is raised too quickly. This is unlikely to be fatal but will stress them for a day or more (according to how dramatic is the rise) and that will compromise the immune system so that they will be at risk of succumbing to something they might have otherwise resisted. To avoid this, unless emergency action is required to raise a crashed pH, it's far better to limit any rise in KH to 20 mg/L (about 1 dKH per day) so the correct amount of sodium bicarbonate to add is 30 grams per 1,000 litres per day or 100 grams per 1,000 (Imp) gallons per day.
Since your swing is probably caused by photosynthesis removing a nocturnal build up of CO2 then it would be best to significantly increase your aeration to gas off dissolved CO2 before you do anything else in order to see what, if any extra action is necessary to limit the swing.
You will probably end up increasing the KH but it's best to limit any adverse effects first.
Read more about alkalinity on my website at:
http://www.mankysanke.co.uk/html/alkalinity.html
Koi can suffer from hardness shock if the KH is raised too quickly. This is unlikely to be fatal but will stress them for a day or more (according to how dramatic is the rise) and that will compromise the immune system so that they will be at risk of succumbing to something they might have otherwise resisted. To avoid this, unless emergency action is required to raise a crashed pH, it's far better to limit any rise in KH to 20 mg/L (about 1 dKH per day) so the correct amount of sodium bicarbonate to add is 30 grams per 1,000 litres per day or 100 grams per 1,000 (Imp) gallons per day.
Since your swing is probably caused by photosynthesis removing a nocturnal build up of CO2 then it would be best to significantly increase your aeration to gas off dissolved CO2 before you do anything else in order to see what, if any extra action is necessary to limit the swing.
You will probably end up increasing the KH but it's best to limit any adverse effects first.
Read more about alkalinity on my website at:
http://www.mankysanke.co.uk/html/alkalinity.html
Re: PH High KH Low
Thanks for the reply
I have put a lot more air into the pond and will see what the PH and KH are like over the next few days before adding Bi Carb
Thanks Susan
I have put a lot more air into the pond and will see what the PH and KH are like over the next few days before adding Bi Carb
Thanks Susan