Major ph confusion

[Supermassive]

My ph straight out of the tap currently is about 6.6. When I tested it a few months ago it was right around 7.0. I know its normal to change through the year and that's not what I'm confused about. GH and KH out of the tap are 120 and 80 and it matches in my tank. What I am confused about is no matter what I do my water always goes up to 7.6-7.8ph after 36ish hours.

I just set up a 10 gallon a couple days ago. I added Seachem Neutral Regulator and Acid Buffer when I filled it. I used the recommended dose for 10 gallons. My ph still went up and is currently 7.6-7.8. There is nothing in the tank that will increase ph. but there is driftwood which should lower it. Also I have set aside tap water in a test tube and tested ph. after 36 hours and it was 7.6-7.8 so I know its not anything from my tank and its just the water.

The same thing was going on in my last 5 gallon tank. I went through a whole ordeal to try and lower my ph and just gave up. Probably spent a couple hours reading articles about ph and hardness. I even contacted Seachem directly and they basically told me to buy a hardness test kit and keep adding neutral regulator every day until it goes down. I did that for about a week and nothing changed. So I pretty much gave up. A while later I decided to get Acid Buffer as well to see if it would do anything and it didn't.

From what I've read if you have really hard water you likely will have a high ph. but my water isn't crazy hard and the test kit I have says KH of 80 or below is generally associated with low ph. I plan on keeping a betta so I guess I should ask if 7.8 is even too high. I've read sources that say people happily keep bettas around 8ph. and I've read some that say if its above 7.4 you should resolve that immediately.

I know I could mix my tap water with RO/DI water but wouldn't that lower my KH which isn't ideal? Should I just do what Seachem recommended and dump in neutral regulator and acid buffer until it comes down and then test regularly to see if it stays down? Should I just not worry about it being 7.8? I've already gone through a lot of effort trying to figure this out and I'm no closer than I was 4 months ago when I was an actual complete beginner. I am still a beginner for sure but I feel like I've learned a ton since then. Thanks for any information or advice.

[Sarina]

In my experience the main reason tap water will increase in pH after a day or so is due to dissolved CO2 in the water. Adding it to your tank will increase the dissolved oxygen and decrease the dissolved CO2, naturally raising the pH. 

I will also note that with a KH of 80ppm doesn't necessarily mean that you will have low pH, it just means that your pH is more stable. Other minerals present can affect pH that will not affect your KH number. Dissolved oxygen also tends to raise pH, so if your tank is well oxygenated this can also affect that number. 

I would recommend not chasing pH. Domestic bettas are very adaptable to higher pH and unless you are seeing health problems that may be related to pH, I would not be too concerned. If you are looking to lower your pH naturally, more plants and fewer water changes can help achieve this, as plants will consume minerals in the water column over time. 

Here is some more info on pH, GH, and KH that might be of interest. 

I will also note that neutral regulator is a phosphate buffer, which can cause algae and bind nutrients that plants need. I would recommend discontinuing the use of that product, as well as the acid buffer. You should also assess whether your aquarium has rocks that will raise the pH over time. Anything containing lime stone will raise the GH and pH, and quite a lot of rocks contain some lime stone. 

[Supermassive]

@Sarina  Thank you very much. That is all very useful information to me. I knew I was worrying too much about it. Less maintenance, I can do that. There are no stones in the tank other than the gravel but I do want to get a piece of dragonstone to hide the filter and heater. The tank is going to be relatively heavily planted. The plants are in the tank now but they are still in their pots. Should I do a big water change to try and remove the neutral regulator?

[Sarina]

@Supermassive I would recommend doing more frequent, smaller water changes to avoid any big swings since your tap water changes pH so drastically. But yes, overall removing the neutral regulator is a good plan. 

[Supermassive]

@Sarina  There isn't fish in the tank right now, just some pest snails. So I was thinking I could do a near 100% water change to remove the neutral regulator all at once. Would it be better to do a bunch of 20% water changes over a couple weeks or just do it all now?

[nabokovfan87]

On 9/2/2023 at 12:12 PM, Supermassive said:

My ph straight out of the tap currently is about 6.6. When I tested it a few months ago it was right around 7.0. I know its normal to change through the year and that's not what I'm confused about. GH and KH out of the tap are 120 and 80 and it matches in my tank. What I am confused about is no matter what I do my water always goes up to 7.6-7.8ph after 36ish hours.

For the sake of clarity, ignore PH for a moment.

KH is what you want to look at.  Here's a chart that explains things a bit more clearly.  Left column is your KH value.  Top right row is your PH value.  The other variable here is going to be how oxygenated is your water.  Based on aeration and KH, then your PH will shift.

I don't manage PH, I manage my KH to get my PH stable from crashing.  60-80 ppm being my minimum range for stability in my tank, PH is 6.8-7.0.
 

 

  

On 9/2/2023 at 12:12 PM, Supermassive said:

I know I could mix my tap water with RO/DI water but wouldn't that lower my KH which isn't ideal? Should I just do what Seachem recommended and dump in neutral regulator and acid buffer until it comes down and then test regularly to see if it stays down? Should I just not worry about it being 7.8? I've already gone through a lot of effort trying to figure this out and I'm no closer than I was 4 months ago when I was an actual complete beginner. I am still a beginner for sure but I feel like I've learned a ton since then. Thanks for any information or advice.

I understand your frustration.  When something like this happens I think the best route is to slow down, pause, and reboot the situation. 

Let's start by running an off-gas test. 

1.  Take a sample of your tap water and test KH, GH, and PH immediately.
2.  Take that same sample of tap water and aerate it for 24 hours to off-gas and stabilize the values.  Re-test after 24 hours.  (this is what your tank should be matching)
3.  Compare results in #2 to the results in your tank.

If #2 and #3 don't match, then you can look at water changes to match parameters a bit more closely.  If you're using RO, use RO for top-offs right now. 

The main goal here is to try to get data on the situation, take a moment to analyze it, and then go ahead and reset the method that makes sense for the data you're using.

Unfortunately seachem didn't clarify for you the products to be using.

Seachem Alkalinity buffer - KH goes up ( which means PH goes up)
Seachem Acid buffer - KH goes down (which means PH goes down)

These are the two products designed to replace use of the neutral regulator in your planted tanks setups. So for clarity, no... you shouldn't just add the neutral regulator until things do something.  Not in this situation.  Let's do nothing, gather data, and get some stability going on.

Edited September 2, 2023 by nabokovfan87

[Supermassive]

@nabokovfan87 So for my ph. to go from 6.6 to 7.6 in 36 hours while the kh is the same means my tap water has a lot of dissolved CO2 when it comes out of the tap and it mostly dissipates in 36ish hours? Or am I missing something? And if that's true I don't know what I can do with that information or what it tells me. Also idk if its relevant but I don't run an airstone and I have occasionally seen a single pearl on one of my plants.

[nabokovfan87]

On 9/2/2023 at 1:59 PM, Supermassive said:

@nabokovfan87 So for my ph. to go from 6.6 to 7.6 in 36 hours while the kh is the same means my tap water has a lot of dissolved CO2 when it comes out of the tap and it mostly dissipates in 36ish hours? Or am I missing something? And if that's true I don't know what I can do with that information or what it tells me. Also idk if its relevant but I don't run an airstone and I have occasionally seen a single pearl on one of my plants.

I added more detail above, but yes.  Per the chart, the higher the PH (based on lower KH) the more co2 is in the water (stagnant water) and when you add that to the aquarium, the co2 off-gasses and then you have the ph shift based on oxygenation.

Oxygenation coming from water movement, surface movement and not purely just use of an airstone.

[Supermassive]

@nabokovfan87 I just set up that test earlier today and I have done the test in the past. I have 3 water samples currently sitting in open test tubes. Today immediately out of the tap GH is 120, KH is 80, and PH is 6.6. I filled my ten gallon 3 days ago on the 30th. I only added the recommended dose of both Neutral Regulator and Acid Buffer plus quite a bit of Easy Green. The PH in the tank today is 7.6-7.8 and the GH and KH are the same as immediately out of the tap today. In the past when I did the off gas test I only tested PH and not GH and KH. The PH would go up to 7.6-7.8 in the past.

I am using RO water for top ups but I was also mixing RO and tap water in a 1:4 ratio when doing water changes to try and get the ph down. It never seemed to affect the PH. I wasn't really monitoring hardness then either. It seems more important than I know. This is by far the most difficult thing for me to understand in the aquarium hobby so far. Thank you very much for trying to help me. I will let you know tomorrow what the test results are.

[nabokovfan87]

On 9/2/2023 at 2:38 PM, Supermassive said:

I have 3 water samples currently sitting in open test tubes.

Just use a measuring cup or bowl or something. Then aerate it with an air stone for 24 hours.

[AllFishNoBrakes]

On 9/2/2023 at 1:12 PM, Supermassive said:

Should I just not worry about it being 7.8?

That’s what I would do. 
 

On 9/2/2023 at 1:33 PM, Sarina said:

I would recommend not chasing pH

I agree with this as well. 
 

I’ve had my tanks up and running for 3+ years and I’ve tested pH maybe 5 times with the actual liquid test. I rarely use the test strips these days, but when I do I take a peek and go “yup, the same as it’s been for 3 years”.

I know my water is lower pH, little to no buffer, and pretty soft. So, I focus on keeping things consistent, and don’t chase numbers the internet tells me I need to have. I keep my environments stable and that has done me very well. Also, I don’t go out purchasing fish that I know prefer the opposite water from what I naturally have as I don’t want to “make” water and again chase numbers the internet tells me I HAVE to have. 
 

With a domestic betta, I’ll bet you’d be just fine. Focus on a healthy, stable ecosystem and that should lead you towards success. 

[nabokovfan87]

On 9/2/2023 at 2:16 PM, nabokovfan87 said:

I added more detail above, but yes.  Per the chart, the higher the PH (based on lower KH) the more co2 is in the water (stagnant water) and when you add that to the aquarium, the co2 off-gasses and then you have the ph shift based on oxygenation.

Oxygenation coming from water movement, surface movement and not purely just use of an airstone.

@Supermassive

My apologies.  A bit of some dyslexia on this one.  The issue could be surface movement.  I was talking with someone who has low KH (2 degrees) and they have near 8.0 PH.  The tank is heavily planted but there's almost no off-gassing or water movement in their setup.  Floating plants and having the filter on such low flow means they have good oxygenation, but not off-gassing. 

Essentially, if they didn't have the plants in there they would be having some serious issues.  In the quote above I had mentioned that a low KH and high PH was indicative of high CO2, but it's indicative of LOW co2.  My confusion. 

I would recommend verifying your surface movement (in your testing as well as your tank is adequate) and then proceed with those tests mentioned above.

[Supermassive]

@nabokovfan87 On my ten gallon I have an Aquaclear 20 turned all the way down. But its still way more flow than was in my last 5 gallon. Ill probably even have to dampen the flow more for a betta to be comfortable. The 5 gallon has a Marina slim 10 HOB. It was turned all the way down to barely a trickle. The PH in my 10 gallon matches what it was in my 5 gallon.

So from my current understanding the only real way I could lower my PH without also lowering KH is to inject CO2? Which in that case ill probably just do nothing. Also I don't have a spare airstone or airpump so I cant aerate my water samples. When I did the off gas test in the past PH wouldn't change after 24hrs but it would after 36-48hrs.

@AllFishNoBrakes Thank you very much. That is what I want to hear. I've seen YouTube videos where people have tens of thousands of dollars in fish and tanks and the person said they only tested PH a single time when they bought the house. I guess google just made me paranoid. I'm glad I decided to join the forum.

[Mmiller2001]

Just worry about GH and KH. PH is irrelevant as a system parameter. It’s really only useful information with CO2 injection.

THERES NO SUCH THING AS A PH CRASH. 
 

Just cut the water with distilled by a third if you want lower KH and GH, resulting in a slightly lower pH. Stop the Seachem products as it’s not necessary.

[nabokovfan87]

On 9/3/2023 at 8:19 AM, Supermassive said:

So from my current understanding the only real way I could lower my PH without also lowering KH is to inject CO2?

I don't think that's the option.

I was helping someone with a similar issue.  Maybe you just need to get one of those baffles to help with flow on the output of the HoB for the betta?  They even have some that point backwards to push the flow against the back glass. 

[Supermassive]

@nabokovfan87 I just cant get a grasp on this. So is it possible to calculate PH based on CO2, oxygen, KH, and GH or does it not work like that?

Oh cool I'll have to look into those baffles. I didn't know that was an option.

[nabokovfan87]

On 9/3/2023 at 1:52 PM, Supermassive said:

So is it possible to calculate PH based on CO2, oxygen, KH, and GH or does it not work like that?

That chart above....

KH and PH can be used to calculate your CO2.

Or

KH and CO2 levels can be used to calculate your PH.

The way to interpret this is to understand that you have your KH value, then you have your PH value based on how oxygen rich your water is, how much surface agitation is there, etc.

[tolstoy21]

Ph is a measurement of a water's alkalinity or acidity. The more Kh your water has, the more basic or alkaline it becomes (and will have a higher Ph) and the more it will be able to buffer the water against becoming acidic. However, certain things like decaying plant matter, fish waste, uneaten food, leaves and wood, CO2, can begin to use up that buffer to a degree and cause a gradual shift downward in Ph. Water with no Kh has no way to buffer the water, so it's less stable and any acidifying element can drastically shift the Ph downward.  So, in the end, Kh both influences the water towards being more basic (higher Ph) and keeps it more stable because of its buffering capacity. 

Now, if your Ph only raises when it's in your aquarium, then there is something in the tank contribution Kh to the water. This can happen with certain types of rock or substrate. I haven't heard of a situation where water will become more basic without their being something influencing it upward, like as rock or crushed coral adding calcium carbonate to the water.  Water, especially with fish and plants present, has a tendency to acidify over time, meaning the Kh becomes exhausted and the Ph shifts downward.

Gh has no relevance towards Ph, acidity or alkalinity of water. You can have a low Ph and a high Gh at the same time. They are independent of one another.

Unless you mix your own water from scratch by making RO and adding the appropriate buffers and minerals to it, then fighting the nature of your tap water tends to be a lost game, at least in my experience. 

Edited September 3, 2023 by tolstoy21

[Supermassive]

Woooow. I think I'm finally starting to understand it. KH is just how much alkalinity is in the water and how much acid it can neutralize. Really high KH means it would take a crazy amount of CO2 or any other acid to change the PH, which is why high KH is generally associated with high PH, and really low KH means small amounts of CO2 or any acid can cause a PH change quickly. So decreasing my KH will cause my PH to drop because it allows the small amount of CO2 to acidify the water more? And I could also lower the PH by making the water more stagnant or by directly injecting CO2? And if I increased my KH and didn't change anything else my PH would likely go up even more because the CO2 from the air does even less to acidify the water?

Am I starting to understand or do I have it all wrong?

Edited September 3, 2023 by Supermassive

[Mmiller2001]

On 9/3/2023 at 5:23 PM, Supermassive said:

KH is just how much alkalinity is in the water

Yes, KH is the amount of carbonates in the water or its alkalinity. However, other factors can influence alkalinity, not just carbonates. Any pH above 7 is alkaline and any pH below 7 is acidic.

On 9/3/2023 at 5:23 PM, Supermassive said:

Really high KH means it would take a crazy amount of CO2 or any other acid to change the PH

No, pH will change at the same rate regardless of alkalinity. The range of that change would just be higher or lower depending on the amount of carbonates in the water.

 

On 9/3/2023 at 5:23 PM, Supermassive said:

And I could also lower the PH by making the water more stagnant

Bad idea, you will reduce gas exchange. Gas exchange is important for keeping good O2 and CO2 levels. That said, the tank will never have more than a few or so ppm of CO2 without injection but will certainly have low O2. These 2 gasses are independent of each other.  

On 9/3/2023 at 5:23 PM, Supermassive said:

or by directly injecting CO2?

Yes, CO2 lowers pH by the way of carbonic acid.

On 9/3/2023 at 5:23 PM, Supermassive said:

PH would likely go up even more because the CO2 from the air does even less to acidify the water?

It lowers the pH regardless and by the same amount regardless of KH, the resulting pH will just fall higher do to higher KH.

Edited September 4, 2023 by Mmiller2001

[Mmiller2001]

I will add that a 0KH tank is more stable than a tank with KH. 

[Supermassive]

On 9/3/2023 at 7:49 PM, Mmiller2001 said:

No, KH is the amount of carbonates in the water. Alkalinity is pH. Any pH above 7 is alkaline and any pH below 7 is acidic.

Okay I misworded that but that is what I meant.

 

On 9/3/2023 at 7:49 PM, Mmiller2001 said:

No, pH will change at the same rate regardless of alkalinity. The range of that change would just be higher or lower depending on the amount of carbonates in the water.

I mean if you have higher alkalinity it will take more acid to make an equal PH change compared to lower alkalinity right?

 

On 9/3/2023 at 7:49 PM, Mmiller2001 said:

Bad idea, you will reduce gas exchange. Gas exchange is important for keeping good O2 and CO2 levels. That said, the tank will never have more than a few or so ppm of CO2 without injection but will certainly have low O2. These 2 gasses are independent of each other.

I'm not going to do that I just wanted to make sure I am understanding things correctly that more stagnant water would in fact lower PH.

[Mmiller2001]

On 9/3/2023 at 6:00 PM, Supermassive said:

Okay I misworded that but that is what I meant.

I made a correction here. You are correct, alkalinity is the waters resistance to acidification.

[Supermassive]

On 9/3/2023 at 7:56 PM, Mmiller2001 said:

I will add that a 0KH tank is more stable than a tank with KH.

Wouldn't that be a bad idea if you have driftwood and Indian almond leaves which I plan to?

[Mmiller2001]

On 9/3/2023 at 6:00 PM, Supermassive said:

I mean if you have higher alkalinity it will take more acid to make an equal PH change compared to lower alkalinity right?

The change occurs the same, but the pH range is just higher.

 

On 9/3/2023 at 6:00 PM, Supermassive said:

I'm not going to do that I just wanted to make sure I am understanding things correctly that more stagnant water would in fact lower PH.

This would depend on other factors in the water. Phosphate buffers water also. Seachem Neutral Regulator uses phosphates to buffer the tank to neutral.

On 9/3/2023 at 6:03 PM, Supermassive said:

Wouldn't that be a bad idea if you have driftwood and Indian almond leaves which I plan to?

Why would it be a bad idea?

Here’s my pH profile over a few days and I run 0KH. There’s no “crash”, it’s all very predictable and is the same weekly.

Edited September 4, 2023 by Mmiller2001