Are Large Water Changes Killing Fish? Small vs Large Water Changes -
- Thread starter tarheel96
- Start date
G
Galantspeedz
koltsixx
Gourami Swami
N
nzafi
- does your water fit this pattern?
Some tap water contains high levels of dissolved CO2 gas. I believe this might explain some of the cases in which fishkeepers insist that large water changes cause harm. I've measured high CO2 levels in the water one county over so I know it's a real problem. And, recently someone posted numbers for water which I calculated must have had well over 125 ppm CO2 from the tap.
That water exited the tap reading pH 6.0 (possibly lower) and increased to 7.8 (the max on the api low-range pH test kit). The 7.8 pH reading was taken after the water had been sitting in a bucket for 24 hours. They didn't have a high-range pH kit so pH could have actually been higher.
Based on these two instances and knowing that many have water which exits the tap at a low pH and then increases to a higher pH (after aging in a bucket or even cup for 24 hours, not in the aquarium), high CO2 levels may very well explain many of these cases. The CO2 level depends on (1) the size of the pH move and (2) the KH of the water. See CO2/pH/KH table.
The easiest way to figure out your CO2 level is to plug your lower pH and KH values into a CO2/pH/KH table. If you don't have a KH test kit (API GH & KH test kit is only about $10) you can estimate your KH using your higher pH value (after 24 hours aging) but that requires some skill and a little guesswork.
In general, CO2 levels over 35 ppm are considered stressful to fish, but these CO2 levels begin decreasing immediately after being added to the aquarium and have normalized to ~2 ppm after 12-24 hours. I'm not sure how high is too high but e.g., if pH increases by 1 point after exiting the tap then the CO2 level can be 45, 90, or 180 ppm depending on whether KH is 2, 4, or 8º. It's difficult to tell how high the level may be without knowing KH but a minimum CO2 level can still be established.
CO2/pH/KH Table
https://barrreport.com/attachments/co2_graph_zps9c124ef0-gif.6317/
CO2 caculator based on pH, KH
http://aquariuminfo.org/co2calculator.html
koltsixx
Gourami Swami
N
nzafi
- does your water fit this pattern?Some tap water contains high levels of dissolved CO2 gas. I believe this might explain some of the cases in which fishkeepers insist that large water changes cause harm. I've measured high CO2 levels in the water one county over so I know it's a real problem. And, recently someone posted numbers for water which I calculated must have had well over 125 ppm CO2 from the tap.
That water exited the tap reading pH 6.0 (possibly lower) and increased to 7.8 (the max on the api low-range pH test kit). The 7.8 pH reading was taken after the water had been sitting in a bucket for 24 hours. They didn't have a high-range pH kit so pH could have actually been higher.
Based on these two instances and knowing that many have water which exits the tap at a low pH and then increases to a higher pH (after aging in a bucket or even cup for 24 hours, not in the aquarium), high CO2 levels may very well explain many of these cases. The CO2 level depends on (1) the size of the pH move and (2) the KH of the water. See CO2/pH/KH table.
The easiest way to figure out your CO2 level is to plug your lower pH and KH values into a CO2/pH/KH table. If you don't have a KH test kit (API GH & KH test kit is only about $10) you can estimate your KH using your higher pH value (after 24 hours aging) but that requires some skill and a little guesswork.
In general, CO2 levels over 35 ppm are considered stressful to fish, but these CO2 levels begin decreasing immediately after being added to the aquarium and have normalized to ~2 ppm after 12-24 hours. I'm not sure how high is too high but e.g., if pH increases by 1 point after exiting the tap then the CO2 level can be 45, 90, or 180 ppm depending on whether KH is 2, 4, or 8º. It's difficult to tell how high the level may be without knowing KH but a minimum CO2 level can still be established.
CO2/pH/KH Table
https://barrreport.com/attachments/co2_graph_zps9c124ef0-gif.6317/
CO2 caculator based on pH, KH
http://aquariuminfo.org/co2calculator.html
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Hello; Just to add some fire to the discussion about source water, consider this. In Harlan County KY near a place called Bob's Creek is a fellow who can set his well water on fire. He showed me one afternoon. He ran some well water into a container and put a butane lighter to it just above the surface. It flamed up a bit. Probably not a house where it is a good idea to smoke on the toilet.
Bear in mind this is the Appalachian region of the USA where natural gas deposits are common. There has also been a bit of new development in terms of getting at the natural gas.
Does this bit of fluff have anything to do with the topic of this thread? I don't see a direct relationship but it is an example of how a person's source water can have issues.
Bear in mind this is the Appalachian region of the USA where natural gas deposits are common. There has also been a bit of new development in terms of getting at the natural gas.
Does this bit of fluff have anything to do with the topic of this thread? I don't see a direct relationship but it is an example of how a person's source water can have issues.
Actually, I was reading earlier today and remember seeing an illustration showing how CO2 being injected deep into the ground wasn't supposed to contaminate groundwater which is much more shallow. I'm not sure what it is and how it relates to hydraulic fracturing but it's interesting now that you mention fracking. It's something different though because CO2 is non-flammable. Here's the link:
https://www.netl.doe.gov/research/coal/carbon-storage/Carbon-Storage-FAQs/co2-in-our-drinking-water
G Galantspeedz
Some tap water contains high levels of dissolved CO2 gas. I believe this might explain some of the cases in which fishkeepers insist that large water changes cause harm. I've measured high CO2 levels in the water one county over so I know it's a real problem. And, recently someone posted numbers for water which I calculated must have had well over 125 ppm CO2 from the tap.
That water exited the tap reading pH 6.0 (possibly lower) and increased to 7.8 (the max on the api low-range pH test kit). The 7.8 pH reading was taken after the water had been sitting in a bucket for 24 hours. They didn't have a high-range pH kit so pH could have actually been higher.
Based on these two instances and knowing that many have water which exits the tap at a low pH and then increases to a higher pH (after aging in a bucket or even cup for 24 hours, not in the aquarium), high CO2 levels may very well explain many of these cases. The CO2 level depends on (1) the size of the pH move and (2) the KH of the water. See CO2/pH/KH table.
The easiest way to figure out your CO2 level is to plug your lower pH and KH values into a CO2/pH/KH table. If you don't have a KH test kit (API GH & KH test kit is only about $10) you can estimate your KH using your higher pH value (after 24 hours aging) but that requires some skill and a little guesswork.
In general, CO2 levels over 35 ppm are considered stressful to fish, but these CO2 levels begin decreasing immediately after being added to the aquarium and have normalized to ~2 ppm after 12-24 hours. I'm not sure how high is too high but e.g., if pH increases by 1 point after exiting the tap then the CO2 level can be 45, 90, or 180 ppm depending on whether KH is 2, 4, or 8º. It's difficult to tell how high the level may be without knowing KH but a minimum CO2 level can still be established.
CO2/pH/KH Table
https://barrreport.com/attachments/co2_graph_zps9c124ef0-gif.6317/
CO2 caculator based on pH, KH
http://aquariuminfo.org/co2calculator.html
not very sure on the CO2 levels but it only affects that 1 particular flowerhorn.
In the tank with the flowerhorn, i have a blood parrot, some angels, a few baby ITs and a sun catfish... only the flowerhorn is affected
Tell it to call my black Nasties to complain about it. I’m sure they have plenty of S to say about me hahaha
tarheel96
not sure why you tagged me, didn't have a chance to read the whole thread. Water changes depend on individual situations. I am fortunate to have hard water so my water stays stable with large water changes but I focus on temperature. I did crash my filter before though. I changed over to a matten filter which needs much longer to stabilize. I did not give it time and continued with large water changes. Result was minicycles and ammonia.Hello; Maybe like the canary in a coal mine type fish. More sensitive than others as had been already mentioned.
If the pH strait from the tap starts of lower and then increases to a higher pH after sitting in a cup or bucket after a day, then water contained CO2 from the tap.
It could exit the tap at pH 6.2 and increase to pH 7.2 after a day or it could exit the tap at pH 7.6 and increase to pH 8.2 after a day. Either way, it increases.
If it does this let me know.
