KH readings

[TwoFace99]

Hello, today I have tested for the first time (using API test kit) my KH and GH readings to understand mainly how much I’m lacking in calcium for my amano shrimp and banana plants (they have spawned several curled leaves). My reading for GH came out to 6dGH.

However, what caught my attention was my KH reading only took one drop to go from blue to yellow (1dKH). Yet, my ph has never fluctuated from a 7.8 reading since I first set up my aquarium. Call me stupid or whatever, but wouldn’t such a low KH cause my pH to swing wildly and greatly stress out my inhabitants until death (it has been a weak now since I got my first batch of fish), while not maintaining a pH of 7.8? Did I perform the test(s) wrong?
 

Also, I did do a few water changes during my cycling process straight from my tap water (living in Chicago). 

[nabokovfan87]

I would test your tap water to compare that to the tank itself.  PH is pretty high, given that KH.  It all ties into the Oxygenation in the water as well as KH to give you that PH value.

If you can get your KH slightly up (min 3) would be good for stability.  The KH drops, then the PH drops.  So your KH might be one now, but then it'll be 0, then your PH would drop.

From an article online:

Quote

A low to very low KH can be dangerous because your water will have a low buffer capacity and the pH will shoot up and down due to small changes in the number of acids or bases. When your KH is low and your pH is unstable you could get into the very unfortunate situation of a 𝗽𝗛 𝗰𝗿𝗮𝘀𝗵.

From the co-op:

https://www.aquariumcoop.com/blogs/aquarium/ph-gh-kh

Edited November 20, 2023 by nabokovfan87

[TwoFace99]

On 11/20/2023 at 5:26 PM, nabokovfan87 said:

I would test your tap water to compare that to the tank itself.  PH is pretty high, given that KH.  It all ties into the Oxygenation in the water as well as KH to give you that PH value.

If you can get your KH slightly up (min 3) would be good for stability.  The KH drops, then the PH drops.  So your KH might be one now, but then it'll be 0, then your PH would drop.

From an article online:

From the co-op:

https://www.aquariumcoop.com/blogs/aquarium/ph-gh-kh

I went ahead and tested my tap and aquarium water, and my tap water came out to 7dKH, while my aquarium water came out to 2dKH (I messed up the reading). I’m not sure what’s affecting the water to drop so drastically. 

[Galabar]

On 11/20/2023 at 3:58 PM, TwoFace99 said:

I went ahead and tested my tap and aquarium water, and my tap water came out to 7dKH, while my aquarium water came out to 2dKH (I messed up the reading). I’m not sure what’s affecting the water to drop so drastically. 

KH (carbonate) is consumed during the nitrification cycle (converting ammonia to nitrate).  So, tap water that starts out at 7dKH will make its way down to 2dKH as carbonate is consumed.

With tap water at 7 dKH, it seems like water changes (and even just top off) should be enough to replenish your tank.

How often do you do water changes (and how much water do you change)?

Edited November 21, 2023 by Galabar

[TwoFace99]

On 11/20/2023 at 6:20 PM, Galabar said:

KH (carbonate) is consumed during the nitrification cycle (converting ammonia to nitrate).  So, tap water that starts out at 7dKH will make its way down to 2dKH as carbonate is consumed.

With tap water at 7 dKH, it seems like water changes (and even just top off) should be enough to replenish your tank.

How often do you do water changes (and how much water do you change)?

The last time I did a water change was the Sunday before last (Nov.12), and it was a 50% water change. 

[tolstoy21]

On 11/20/2023 at 5:44 PM, TwoFace99 said:

Call me stupid or whatever, but wouldn’t such a low KH cause my pH to swing wildly and greatly stress out my inhabitants until death.

Not necessarily. It depends on the species of fish. Your KH won't really swing up, unless you add something to boost it. But it will drop over time if you have things breaking down in the aquarium and acidifying the water. Some fish can deal with the drop, others, those that prefer a neutral to alkaline environment, might get stressed out.

I am perplexed that your aquarium  always reads Ph 7.8 yet has no Kh. That does sound like one of the two readings is off.

I don't think plants utilize Kh, but they do utilize the magnesium in your Gh, and 6 dGh should be enough for plants, unless your Gh is 100% magnesium. 

As for shrimp, I'm not 100% sure (and I could be totally wrong) that they utilize the calcium in Kh either (it's really calcium bicarbonate -- C2HsCaO6 -- and not Calcium -- Ca).  Many species of Caridina shrimp thrive in water below 7 ph (all the way down to 5ph). It's the Gh they need.

Someone please feel free to school me if I am incorrect about the above.

Edited November 21, 2023 by tolstoy21

[tolstoy21]

On 11/20/2023 at 6:58 PM, TwoFace99 said:

I went ahead and tested my tap and aquarium water, and my tap water came out to 7dKH, while my aquarium water came out to 2dKH (I messed up the reading). I’m not sure what’s affecting the water to drop so drastically. 

Ah just saw this now.

And @Galabar is correct in his explanation of a water's buffer (Kh) depleting over time.

[TwoFace99]

On 11/20/2023 at 7:01 PM, tolstoy21 said:

Ah just saw this now.

And @Galabar is correct in his explanation of a water's buffer (Kh) depleting over time.

 

On 11/20/2023 at 6:55 PM, tolstoy21 said:

Not necessarily. It depends on the species of fish. Your KH won't really swing up, unless you add something to boost it. But it will drop over time if you have things breaking down in the aquarium and acidifying the water. Some fish can deal with the drop, others, those that prefer a neutral to alkaline environment, might get stressed out.

I am perplexed that your aquarium  always reads Ph 7.8 yet has no Kh. That does sound like one of the two readings is off.

I don't think plants utilize Kh, but they do utilize the magnesium in your Gh, and 6 dGh should be enough for plants, unless your Gh is 100% magnesium. 

As for shrimp, I'm not 100% sure (and I could be totally wrong) that they utilize the calcium in Kh either (it's really calcium bicarbonate -- C2HsCaO6 -- and not Calcium -- Ca).  Many species of Caridina shrimp thrive in water below 7 ph (all the way down to 5ph). It's the Gh they need.

Someone please feel free to school me if I am incorrect about the above.

I’m assuming my GH is heavily magnesium, since one of my banana plant have sprouted 6 large new leaves that have curled so far, while the other has sprouted a new leaf that’s smaller, but is slowly curling as well. Luckily, my amano shrimp haven’t shown any signs so far of poor health.
Yes, you’re correct shrimp need calcium and magnesium to help with their molting processes/maintaining a strong carapace/stability of their exoskeletons.

I was trying to hold off on any water changes until I received my wonder shells, so I can solve the calcium deficiency in my aquarium, but looks like there’s been a change of plans if I don’t want my KH to dip any further. 
 

Also, my other inhabitants are 2 Angelfish and 2 Bolivian Rams (both groups juveniles). 

Edited November 21, 2023 by TwoFace99

[tolstoy21]

On 11/20/2023 at 8:33 PM, TwoFace99 said:

Also, my other inhabitants are 2 Angelfish and 2 Bolivian Rams (both groups juveniles). 

Those fish should have no problems with handling a Ph between 6.0 and 7.0. You can always add WonderShells to the aquarium to boost calcium and trace elements.

[TwoFace99]

On 11/20/2023 at 7:44 PM, tolstoy21 said:

Those fish should have no problems with handling a Ph between 6.0 and 7.0. You can always add WonderShells to the aquarium to boost calcium and trace elements.

That’s what I am planning on doing, but my wonder shells haven’t arrived yet, so I can’t solve all my issues in one go unfortunately. Do you know if wonder shells can be added straight into an aquarium after a water change rather than during?

[tolstoy21]

I think you just put them in and they dissolve slowly. But I could be wrong as I have never used them. 

[nabokovfan87]

On 11/20/2023 at 3:58 PM, TwoFace99 said:

I went ahead and tested my tap and aquarium water, and my tap water came out to 7dKH, while my aquarium water came out to 2dKH (I messed up the reading). I’m not sure what’s affecting the water to drop so drastically. 

Essentially it points to not doing water changes often enough or doing too small of a volume of water change.

[tolstoy21]

On 11/20/2023 at 8:33 PM, TwoFace99 said:

Luckily, my amano shrimp haven’t shown any signs so far of poor health.

I don't know much about keeping amano shrimp, but I can attest that both caridina and neocaridina shrimp do fine in a Ph down to 6.0. My caridina handle a Ph down into the 5s.  So acidic conditions and lack of Kh apparently have no affect on their shells. In fact, caridina are not very happy in anything 7.0 or above. 

I also have ramshorn snails that do fine in the mid-6 Ph range. In fact, if they are not kept in check, they completely overrun some of my shrimp tanks. I don't see them start to die off until I push the Ph down below 6.  However, I do have a hard time keeping mystery and nerite snails in my water, which is pretty acidic.

Edited November 21, 2023 by tolstoy21