Is my water hard?

[Naughts]

My tank has a PH of 8.0, a KH of 40, and a GH of 120. Does this translate to hard alkaline water?

 

[Jan Cavalieri]

You have just barely alkaline water (8-14) is the term "alkaline" as used when referring to pH. Unless you have some fish especially picky about PH I wouldn't worry about it - or try adding 1/2 capful of PHdown made by API. That should bring it down to about 7.5. I've been lectured by far more experienced people than myself on this forum that messing with PH is rarely a good idea (especially when you're so close), but if you want 7 on the money - wait a day and do a water change and a water test and then add another 1/2 capful if necessary - that should bring it down to "normal" of 7 or 7.2, You KH isn't worth worrying about - it's pretty normal. Your GH is barely high. (kind of like your PH is barely high). I would recommend a water change and add some water conditioner product made by Seachem or API. In fact, you could start with the water softener after a water change before you do anything and see if that brings the PH down into the 7's and - your GH down to 20 or so- overall you seem to have decent water (In my city a "normal" pH is about 10.00 - but our hardness isn't too horrible (it used to be - I can tell by the crusty water faucets in an older house) so they must now add conditioners) but I always have to adjust my pH on a new tank, usually (but not always) once adjusted, it doesn't change too terribly much - maybe a couple of decimal points, after a long series of water changes my pH is back up into the 8.5's or so - way too high for SOME of my fish - fine for the others and I lower my PH again. Glad it's not something I have to do repeatedly - my understanding from this forum is that it is NOT a good idea to go messing with pH.

 

[Naughts]

Thank you Jan, that is helpful and the good news I was hoping for. I tried PH down a couple of months ago, it took 4 days to get it to 7 then 4 days later it was back at 8! I think this yo-yo effect caused the death if one of my neocardinia shrimp so I binned the PH down. I can't really get my head round the GH/KH yet but am very happy to hear it's not extreme. I haven't used the other additives but will look them up. Thank you for the help and time

 

[seangee]

How and when are you testing your water?
You also need to specify what units the hardness refers to. I am assuming you mean ppm. If my assumption is correct your water is fairly soft in fishkeeping terms and your water is suitable for a lot of species, but not livebearers.

To test your pH collect some water from your tap in a clean container and test it after 24 hours. SOmetimes water companies change the pH of tap water for various reasons and this will allow it to stabilise to its "normal" level. Also test some water from your tank at least 24 hours after putting it in. This is to establish of there is anything in your tank that is affecting the pH.

Hardness is far more important to fish than pH and you should choose fish that do well in your water. If the numbers you mentioned are correct you are fortunate in that there are a lot of species that would thrive in that water. On the other hand pH is important in that it should be kept stable. Fish do not cope well with changes in pH. Most people recommend changing between 50 and 75% of your water every week. If you are going to meddle with the water this means a lifetime of testing and manipulating water (and risk). So it really is better to just choose the right fish for your water.

 

[seangee]

Thank you Jan, that is helpful and the good news I was hoping for. I tried PH down a couple of months ago, it took 4 days to get it to 7 then 4 days later it was back at 8! I think this yo-yo effect caused the death if one of my neocardinia shrimp so I binned the PH down. I can't really get my head round the GH/KH yet but am very happy to hear it's not extreme. I haven't used the other additives but will look them up. Thank you for the help and time

Our post crossed. Your water should be fine for cherry shrimp as is. You don't need to do anything. Are you seeing berried females? Or have you had any new shrimplets? If so that's a pretty good sign that all is well.

 

[Byron]

Thank you Jan, that is helpful and the good news I was hoping for. I tried PH down a couple of months ago, it took 4 days to get it to 7 then 4 days later it was back at 8! I think this yo-yo effect caused the death if one of my neocardinia shrimp so I binned the PH down. I can't really get my head round the GH/KH yet but am very happy to hear it's not extreme. I haven't used the other additives but will look them up. Thank you for the help and time

This is exactly why you must never use pH adjusting chemicals in an aquarium. The fluctuating pH is very hard on fish, and weakens them and this can be permanent leading to troubles down the road.

The pH is tied to other factors such as the GH (general hardness), KH (carbonate hardness or Alkalinity), CO2 (dissolved carbon dioxide in the water) to name a few. These all impact the pH. The pH down and similar chemicals do nothing with respect to these other factors, and this is why the pH lowered initially but went right back up. The GH, and especially the buffering capability of the KH, will prevent adjustments to the pH, at least up to the point where you use so much chemical it literally drowns the chemistry and the pH can then crash. This will almost inevitably result in dead fish.

The only way to safely adjust pH is by adjusting the GH and KH first, and the pH will follow suit. Your GH at 120 ppm (I am assuming this is ppm, or mg/l which is identical) equates to 6.7 dGH. The hobby uses either ppm (parts per million, which is the same value as mg/l) or dGH so I like to include both. This is not extreme at all, somewhere around moderately hard but at thee low end. The KH at 40 ppm will buffer the pH, as you've seen and I explained above. If you were to dilute the source water with "pure" water it would decrease the GH/KH and the pH might lower as a result. Until you do these changes it is difficult to predict the result because of all the factors involved. Which is one big reason so many of us caution members not to try. Water chemistry is indeed complex, and any change in one factor is likely to have a chain reaction that might be completely opposite to the intention.

So to your initial question, no this is not hard alkaline water. It is moderate, perhaps moderately hard at the low end. The pH is basic--what used to be termed alkaline but that term is no longer used for pH as it has a different scientific meaning relating to the carbonate hardness. There may be other factors keeping the pH high but you/we would need to look into other additives the water authority may be using and the specifics of your aquarium. For example, if you have calcareous rock or a substrate composed of calcareous substances (limestone, coral, shells, aragonite, etc) this will dissolve slowly, increasing the pH faster than the GH/KH.

 

[Naughts]

I have the APi liquid test kit which does the high PH. I borrowed my daughter's APi test strip for GH and KH, this is 120 ppm and 40ppm. I test every third day before any water change, in the evening. I have neon tetra which is why I tried to reduce the PH before.

Tap water is PH 8.0. My daughter's betta tank (same water) seems to have a PH of 7.0 but that might just be because she uses test strips instead of liquid? (she's 13 so does some maintenance herself but I don't give her chemicals).

Thank you for the advise and information

 

[Byron]

I have the APi liquid test kit which does the high PH. I borrowed my daughter's APi test strip for GH and KH, this is 120 ppm and 40ppm. I test every third day before any water change, in the evening. I have neon tetra which is why I tried to reduce the PH before.

Tap water is PH 8.0. My daughter's betta tank (same water) seems to have a PH of 7.0 but that might just be because she uses test strips instead of liquid? (she's 13 so does some maintenance herself but I don't give her chemicals).

Thank you for the advise and information

There is something here that you /we need to sort out. First thing is, what is the pH of the tap water on its own? You say it is 8, and if it remains 8 in your aquarium but lowers to 7 in your daughters' aquarium, there is something we are not seeing.

Tap water. First, let a glass of tap water sit for 24 hours and then test the pH. This will out-gas the CO2 (if any). Second, do you know if the water authority are adding any substance to the water (not thinking of chlorine)? Some do this to increase the pH (regardless of GH and KH) but it is usually temporary.

Your aquarium, is there any possibly calcareous rock in this tank, or is the substrate calcareous?

 

[Naughts]

I had a berries shrimp but didn't get shrimplets. I don't see the shrimps much at all these days, maybe they avoid the fish or maybe they just have found good hiding spots.

 

[Naughts]

This is exactly why you must never use pH adjusting chemicals in an aquarium. The fluctuating pH is very hard on fish, and weakens them and this can be permanent leading to troubles down the road.

The pH is tied to other factors such as the GH (general hardness), KH (carbonate hardness or Alkalinity), CO2 (dissolved carbon dioxide in the water) to name a few. These all impact the pH. The pH down and similar chemicals do nothing with respect to these other factors, and this is why the pH lowered initially but went right back up. The GH, and especially the buffering capability of the KH, will prevent adjustments to the pH, at least up to the point where you use so much chemical it literally drowns the chemistry and the pH can then crash. This will almost inevitably result in dead fish.

The only way to safely adjust pH is by adjusting the GH and KH first, and the pH will follow suit. Your GH at 120 ppm (I am assuming this is ppm, or mg/l which is identical) equates to 6.7 dGH. The hobby uses either ppm (parts per million, which is the same value as mg/l) or dGH so I like to include both. This is not extreme at all, somewhere around moderately hard but at thee low end. The KH at 40 ppm will buffer the pH, as you've seen and I explained above. If you were to dilute the source water with "pure" water it would decrease the GH/KH and the pH might lower as a result. Until you do these changes it is difficult to predict the result because of all the factors involved. Which is one big reason so many of us caution members not to try. Water chemistry is indeed complex, and any change in one factor is likely to have a chain reaction that might be completely opposite to the intention.

So to your initial question, no this is not hard alkaline water. It is moderate, perhaps moderately hard at the low end. The pH is basic--what used to be termed alkaline but that term is no longer used for pH as it has a different scientific meaning relating to the carbonate hardness. There may be other factors keeping the pH high but you/we would need to look into other additives the water authority may be using and the specifics of your aquarium. For example, if you have calcareous rock or a substrate composed of calcareous substances (limestone, coral, shells, aragonite, etc) this will dissolve slowly, increasing the pH faster than the GH/KH.

Thank you for all the helpful information Byron.

 

[Naughts]

There is something here that you /we need to sort out. First thing is, what is the pH of the tap water on its own? You say it is 8, and if it remains 8 in your aquarium but lowers to 7 in your daughters' aquarium, there is something we are not seeing.

Tap water. First, let a glass of tap water sit for 24 hours and then test the pH. This will out-gas the CO2 (if any). Second, do you know if the water authority are adding any substance to the water (not thinking of chlorine)? Some do this to increase the pH (regardless of GH and KH) but it is usually temporary.

Your aquarium, is there any possibly calcareous rock in this tank, or is the substrate calcareous?

Ok, thank you. I will post the tap water test after 24 hours. My tank has no rock, it has biorb media (inert

There is something here that you /we need to sort out. First thing is, what is the pH of the tap water on its own? You say it is 8, and if it remains 8 in your aquarium but lowers to 7 in your daughters' aquarium, there is something we are not seeing.

Tap water. First, let a glass of tap water sit for 24 hours and then test the pH. This will out-gas the CO2 (if any). Second, do you know if the water authority are adding any substance to the water (not thinking of chlorine)? Some do this to increase the pH (regardless of GH and KH) but it is usually temporary.

Your aquarium, is there any possibly calcareous rock in this tank, or is the substrate calcareous?

Thank you, I will post the tap water result after 24 hours. Sorry I don't know what the water authority add. The tap water does test 10ppm for nitrate. I have no rock. My substrate is biorb ceramic media (inert?). Thank you for your help.

 

[Naughts]

There is something here that you /we need to sort out. First thing is, what is the pH of the tap water on its own? You say it is 8, and if it remains 8 in your aquarium but lowers to 7 in your daughters' aquarium, there is something we are not seeing.

Tap water. First, let a glass of tap water sit for 24 hours and then test the pH. This will out-gas the CO2 (if any). Second, do you know if the water authority are adding any substance to the water (not thinking of chlorine)? Some do this to increase the pH (regardless of GH and KH) but it is usually temporary.

Your aquarium, is there any possibly calcareous rock in this tank, or is the substrate calcareous?

So I had a slight change in the result this time, tap water sat for 24 hours PH 7.6.
Water authorities info:
PH 7.58.
Hardness level is slightly hard with Hardness Clark 9.54, Hardness German 7.63, Hardness French 13.63- very confused with all these numbers!
Ammonium <0.013mg/l
Chloride 41.41mg/l
Free chlorine <0.30 mg/l
Nitrate 23.34mg/l
Nitrite < 0.006
Nitrite-Nitrate calculated 0.47
I am not sure what is relevant so may have excluded /included the wrong reports.

My tank has some very old (30 years!) Bogwood but it isnt disintegrating or anything.

 

[Essjay]

PH 7.58.
Hardness level is slightly hard with Hardness Clark 9.54, Hardness German 7.63, Hardness French 13.63- very confused with all these numbers!
Nitrate 23.34mg/l

These are the figures of most importance. Ammonia and nitrite are so low we could never detect them with our test kits.

Your pH in tap water that's been allowed to sit is just about the same as the water company's figure.

Hardness has several units as you can see. The ones used in fish keeping are German degrees, which you'll see written as dGH, dH or just degrees, and ppm, which is also called mg/l. You water company gives German degrees, so your dH is the same at 7.63. This converts to 136.6 ppm (there is a converter in the calculator section of How To Tips)
This is slightly harder than your test strips show, but as there is a big difference between values for the colours on the strip they are not terribly accurate.

Your tap water nitrate as slightly above the maximum level needed for fish (that's 20 ppm). Live plants in the tank will help with that.


UK water companies rarely give KH (which they call alkalinity) so we can only go by the result on the strips. 40 ppm converts to 2.2 degrees, which is quite low. With a KH this low I would expect your pH in the tank to fall slightly, as your daughter's tank does. This is because nitrate and organic products that build up in the tank are acidic. The question remains - why is your tank pH higher than your tap water pH after it has stood?
We know you have no rocks in your tank, but do you have any coral or even shells?

 

[Naughts]

These are the figures of most importance. Ammonia and nitrite are so low we could never detect them with our test kits.

Your pH in tap water that's been allowed to sit is just about the same as the water company's figure.

Hardness has several units as you can see. The ones used in fish keeping are German degrees, which you'll see written as dGH, dH or just degrees, and ppm, which is also called mg/l. You water company gives German degrees, so your dH is the same at 7.63. This converts to 136.6 ppm (there is a converter in the calculator section of How To Tips)
This is slightly harder than your test strips show, but as there is a big difference between values for the colours on the strip they are not terribly accurate.

Your tap water nitrate as slightly above the maximum level needed for fish (that's 20 ppm). Live plants in the tank will help with that.


UK water companies rarely give KH (which they call alkalinity) so we can only go by the result on the strips. 40 ppm converts to 2.2 degrees, which is quite low. With a KH this low I would expect your pH in the tank to fall slightly, as your daughter's tank does. This is because nitrate and organic products that build up in the tank are acidic. The question remains - why is your tank pH higher than your tap water pH after it has stood?
We know you have no rocks in your tank, but do you have any coral or even shells?

Thank you for the explanation and info.
No, no corals or shells.
I will keep adding more plants for the nitrate, Thank you.
I've ordered some catappa leaves but am not holding out much hope that it will change the ph.

 

[Byron]

Thank you for the explanation and info.
No, no corals or shells.
I will keep adding more plants for the nitrate, Thank you.
I've ordered some catappa leaves but am not holding out much hope that it will change the ph.

It should lower the pH with several of them, given the KH, but if the pH really is still at 8 in this tank when it is only 7 in your daughter's and 7.5-7.6 in the source tap water, there is something in this tank increasing it and without knowing what that is we cannot tell how much it may lower if at all. Given the numbers we have here, the pH lowering as it does in your daughter's tank is what one would expect.

BTW, I agree with all essjay posted in post #13.