Struggling with kH and pH. At a loss🤔

[Jamiel]

my kH is zero. As in just one drop on the API test and it’s immediately yellow. I don’t even see blue. My pH reads 6.0 ph, which is as low as the chart goes so it could be even lower than that.

I’ve currently got 3 aquariums on the go, all of them have been running for at least 3 months, the longest over a year. Over that time I have NEVER had even a slight reading of nitrite or nitrate in any of them, but I do regularly get very slight readings of ammonia. Now I don’t know if this is false readings or what. But the fact I do get readings for ammonia but never nitrite or nitrate makes me worry my pH is just too low for the nitrogen cycle to occur.

My tap ph does come out at about 6.4/6.6, but I think the breakdown of wood tannings and botanical alongside the lack of any kh just causes a rapid ph drop. I did a 70% water change in one tank yesterday. Today the ph is already <6.

I understand that much of ammonia concetrations are ionised at lower ph’s to become ammonium which is nearly harmless to fish, meaning despite ammonia readings fish should be safe (this is partly how fish are able to live in natural black water).

Now I don’t know what to do here. Do I just carry on as I am assuming the the ammonia is due to the ph safe for the fish or should I buffer my water. I just worry my ph is TOO low for many of the fish species I keep (and in particular my neocaridina shrimp).

I’m considering adding some potassium bicarbonate, but the problem then is toxify the ammonia into dangerous ammonia as my ph rises.

Ugh I just don’t know what to do and would love some insight on this!

Many thanks
Jamie

 

[Maf 2500]

Water like that is perfect for rainforest fish and many here would love to have that "problem". However I can see that it is not ideal for neocaradina. I wouldn't bother with any of the chemical buffers sold by Seachem and the like. The easiest way to gently buffer the water is to add a limestone rich rock (eg Seiryu stone) or two and the surface of the stone will very, very slowly dissolve raising the KH and GH in tandem as the calcium carbonate is released. If it makes the water too hard for your liking reduce the number/size of the stones until you reach a nice balance.

 

[Bradders]

My tap ph does come out at about 6.4/6.6, but I think the breakdown of wood tannings and botanical alongside the lack of any kh just causes a rapid ph drop. I did a 70% water change in one tank yesterday. Today the ph is already <6.

I would be very interested to find out what your pH is a couple of days after a water change. I can only assume you probably have a very low TDS as well.

I just worry my ph is TOO low for many of the fish species I keep (and in particular my neocaridina shrimp).

Can you give us an idea of the fish you are keeping? Including how long you have had them, health etc.

 

[Andy Pierce]

You don't have any carbonate buffering capacity, which is fine for many purposes (there are some species that require/prefer a higher pH). Your neocaridina need some GH, but not necessarily any KH (others might disagree on this KH point). Some light remineralisation with either ready-made e.g. Salty Shrimp or custom added salts can sort this straightforwardly for you. No need to panic. What type of test are you using for ammonia? You're right that at your pH all ammonia will be in the ammonium ion form.

 

[Marcel G]

It is difficult to give advice without knowing the pH. If you are concerned about the pH being too low, then [in my humble opinion] you should first of all find out what pH you actually have in there. Only then can the next course of action be determined. Water without bicarbonates (i.e. with a zero alkalinity) has a pH of around 5.5.

The pH can be manipulated either in a natural way or in a not-so-natural way.

More or less natural ways of changing pH:

1) If your goal is to decrease pH:

• add ammonium (NH4) source => its conversion (via nitrification) produces acidic hydrogen ions as a by-product, which lower the pH
• add CO2 to the water [at a reasonable amount]

2) If your goal is to increase pH:

• remove ammonium (NH4) from the fertilizer and replace it with nitrate (NO3) => this eliminates nitrification and the associated production of acidic hydrogen ions
• add some limestone to the water => as it slowly dissolves, bicarbonate (HCO3) will be released into the water, raising the pH
• add baking soda (NaHCO3) or any other (bi)carbonate compound to the water => in this way it is possible to raise the pH to a maximum of 8.3

Dangerous ways of changing pH (I don't recommend this, but I list it here for completeness):

1) If your goal is to decrease pH:

• add a strong acid (e.g. HCl) => this is very dangerous and you need to measure the appropriate amount carefully and know what you do

2) If your goal is to increase pH:

• add a strong base (e.g. NaOH) to the water => this is very dangerous and you need to measure the appropriate amount carefully and know what you do

 

[Jamiel]

Water like that is perfect for rainforest fish and many here would love to have that "problem". However I can see that it is not ideal for neocaradina. I wouldn't bother with any of the chemical buffers sold by Seachem and the like. The easiest way to gently buffer the water is to add a limestone rich rock (eg Seiryu stone) or two and the surface of the stone will very, very slowly dissolve raising the KH and GH in tandem as the calcium carbonate is released. If it makes the water too hard for your liking reduce the number/size of the stones until you reach a nice balance.

Yes I understand in many ways I’m lucky and it’s great for my cichlids and other acid loving fish. It’s more my neocaradina and rice fish I worry for. I have used crushed coral in the past in my main large South American tank (acid loving fish yes, but decided to try to add somewhat of a buffer just as a safety blanket) but the water volume was just so large I’m not sure it had much of an effect. Maybe I’ll do it again but in my smaller tanks, or try a limestone rock as you say.

 

[Jamiel]

I would be very interested to find out what your pH is a couple of days after a water change. I can only assume you probably have a very low TDS as well.


Can you give us an idea of the fish you are keeping? Including how long you have had them, health etc.

My main large tank is mostly Amazonian cichlids (of course soft water lovers so not to worried about these). Fairly established tanks full of healthy fish. The tank is fairly ‘biotoopey’ meaning few plants in the aquarium itself (mainly due to some fish being plant destroyers) but it does have a dense growth of house plants growing emersed from the tank. I imagine even if the soft/acidic conditions are not ideal for the ‘conventional’ beneficial bacteria to grow, the plants will atleast be filling in and removing excess nutrients.

My other two tanks are stocked with rice fish, heavily planted. Of course very hardy and adaptable but with a preference for hard more basic water. I’ve had no issues keeping them in such conditions but I would still prefer to at least replicate slightly more ideal conditions for them. a

And the other tank just cherry shrimp which I’m a little more concerned for. Also heavily planted with emersed house plant growth as well. I have had a few shrimp deaths from mismoults so I do think I need to remineralise the water.

As I say, in terms of pH even just the day after a water change I’m at a maximum of pH 6. Perhaps I need to invest in a different test kit that can test even more acidic than that.

 

[Jamiel]

You don't have any carbonate buffering capacity, which is fine for many purposes (there are some species that require/prefer a higher pH). Your neocaridina need some GH, but not necessarily any KH (others might disagree on this KH point). Some light remineralisation with either ready-made e.g. Salty Shrimp or custom added salts can sort this straightforwardly for you. No need to panic. What type of test are you using for ammonia? You're right that at your pH all ammonia will be in the ammonium ion form.

API test. I do know they are known for reading false 0.25 reading positives. It’s just the fact that I have NEVER had a reading for nitrite or nitrate. Not once, which makes me wonder if there is even any nitrification going on in my tanks at all.

 

[Jamiel]

It is difficult to give advice without knowing the pH. If you are concerned about the pH being too low, then [in my humble opinion] you should first of all find out what pH you actually have in there. Only then can the next course of action be determined. Water without bicarbonates (i.e. with a zero alkalinity) has a pH of around 5.5.

The pH can be manipulated either in a natural way or in a not-so-natural way.

More or less natural ways of changing pH:

1) If your goal is to decrease pH:

• add ammonium (NH4) source => its conversion (via nitrification) produces acidic hydrogen ions as a by-product, which lower the pH
• add CO2 to the water [at a reasonable amount]

2) If your goal is to increase pH:

• remove ammonium (NH4) from the fertilizer and replace it with nitrate (NO3) => this eliminates nitrification and the associated production of acidic hydrogen ions
• add some limestone to the water => as it slowly dissolves, bicarbonate (HCO3) will be released into the water, raising the pH
• add baking soda (NaHCO3) or any other (bi)carbonate compound to the water => in this way it is possible to raise the pH to a maximum of 8.3

Dangerous ways of changing pH (I don't recommend this, but I list it here for completeness):

1) If your goal is to decrease pH:

• add a strong acid (e.g. HCl) => this is very dangerous and you need to measure the appropriate amount carefully and know what you do

2) If your goal is to increase pH:

• add a strong base (e.g. NaOH) to the water => this is very dangerous and you need to measure the appropriate amount carefully and know what you do

You may have missed it but I have actually specified my pH in the original post. It’s at the highest 6, but potentially lower since the API test does not test for lower than that.

I think I’m going to add some dennerle shrimp remineralisation and see how that goes. I’ve also got some potassium bicarbonate in the way which I’ll experiment with in a bucket of water and go from there.

 

[dw1305]

Hi all,

I imagine even if the soft/acidic conditions are not ideal for the ‘conventional’ beneficial bacteria to grow, the plants will atleast be filling in and removing excess nutrients.

I honestly wouldn't worry, I think those are the important bits:

• Plants are much <"more efficient at nutrient removal"> than most aquarium literature acknowledges, and
• The microbes that actually occur in aquariums don't require high carbonate hardness or high TAN levels.

One advantage we have at UKAPS is that we've actually talked to scientists at the cutting edge of research into nitrification, details are in <"Correspondence with Dr Ryan Newton - School of Freshwater Sciences, University of Wisconsin—Milwaukee"> & <"Correspondence with the Neufeld lab. University of Waterloo">.

cheers Darrel

 

[dw1305]

Hi all,

API test. I do know they are known for reading false 0.25 reading positives.

Do you Prime or similar as your water conditioner? If you do it may interfere with TAN ammonia test kit readings.

It’s just the fact that I have NEVER had a reading for nitrite or nitrate. Not once, which makes me wonder if there is even any nitrification going on in my tanks at all.

It could be that the plants are very efficiently removing <"all forms of fixed nitrogen"> from your tank, but it is more likely <"to be the test kit">.

Both Estimative and <"Duckweed Indices"> were developed, at least partially, to do away with a <"requirement for nitrate testing">.

cheers Darrel

 

[Andy Pierce]

API test. I do know they are known for reading false 0.25 reading positives. It’s just the fact that I have NEVER had a reading for nitrite or nitrate. Not once, which makes me wonder if there is even any nitrification going on in my tanks at all.

You should have piles of nitrate in your tank, but nitrate is also notoriously difficult to measure accurately with standard tests. If your plants and livestock look good, I would just take the win.

 

[dw1305]

Hi all,
I don't see it as a big problem, it is a relatively straightforward to make <"water harder and more alkaline">.

I have used crushed coral in the past

You can use "Oyster (or Cockle) Shell Chick Grit", it is still CaCO3, but a lot cheaper (about £2 a kilo from P@H etc) and more environmentally friendly.

You also get a negative feedback loop with any solid limestone buffer, the lower the pH of the water is the more quickly the CaCO3 goes into solution. When / if you get to 18 dGH and 18 dKH? The water fully saturated carbonates and and dissolution stops.

Our tap water is already <"18 dGH / 18 dKH">, so I just use a very small proportion of that as my "remineralising agent".

I’ve also got some potassium bicarbonate

That will work more quickly.

cheers Darrel

 

[Jamiel]

Hi all,

Do you Prime or similar as your water conditioner? If you do it may interfere with TAN ammonia test kit readings.

It could be that the plants are very efficiently removing <"all forms of fixed nitrogen"> from your tank, but it is more likely <"to be the test kit">.

Both Estimative and <"Duckweed Indices"> were developed, at least partially, to do away with a <"requirement for nitrate testing">.

cheers Darrel

I do use Seachem Prime actually, it never occurred to me that this could interfere with readings. Maybe I’ll try another conditioner, maybe API and see if I still see a small amount of ammonia?

 

[Marcel G]

You may have missed it but I have actually specified my pH in the original post. It’s at the highest 6, but potentially lower since the API test does not test for lower than that.
I think I’m going to add some dennerle shrimp remineralisation and see how that goes. I’ve also got some potassium bicarbonate in the way which I’ll experiment with in a bucket of water and go from there.

No, I didn't miss it, which is why I wrote that unless you can determine your pH more accurately, it's hard to give advice. If your nitrification is working well (and if you have, say, an extra dead shrimp in your tank), your pH could easily drop to 3-4 in a few weeks. But the addition of bicarbonate should raise it reliably. Except that some of the more sensitive plants (if you have any or plan to have any) may have a problem with bicarbonates.

 

[Jamiel]

No, I didn't miss it, which is why I wrote that unless you can determine your pH more accurately, it's hard to give advice. If your nitrification is working well (and if you have, say, an extra dead shrimp in your tank), your pH could easily drop to 3-4 in a few weeks. But the addition of bicarbonate should raise it reliably. Except that some of the more sensitive plants (if you have any or plan to have any) may have a problem with bicarbonates.

Ahh, I see you what you’re saying now. Yes I’m going to work on raising it a bit and test again.