Why is my KH pH and GH increasing?

[sparkypenguin]

Hi all,

Hoping for some help with regards to recent changes in my water parameters....

Some info about my set up starting with a photo to set the scene .........

I have an established freshwater 4 foot 90g tank which contains:
2 Red Robin Honey Gouramis - approx. 2" in size.
10 Neon Tetras - 5 adult and 5 young.
7 Wag Tail Platys - 3 adults and 3 young - all now female to prevent further fry!
5 Panda Corys - Varying sizes, 1 of which was born in the tank and discovered when it was about 15mm long.
7 Dalmatian Mollys - 3 adults and 4 young - all now female to prevent further fry!
2 Bristle Nose Plecs - about 1" long and as yet unsexed.
2 Apple Snails - about 1" in size
And probably 30-40 Molly fry which will be going to a local fish shop once they are a bit bigger.

The substrate is a layer of aquatic sand varying from 0 to 1" and averaging at about 1/2 " in depth, I do not vacuum this at all.
I have several large of pieces of bogwood, 2 half coconut shells, plastic plants, a few oxygenators and several pieces of plastic pipe.
I have an internal filter with a UV light and oxygen input and at the other end of the tank a large external filter input which returns at surface level via a spray bar.
Both filters only contain sponge and ceramic media, no carbon or any pH / Hardness altering media.
I have 1 air pump to further agitate the water surface.
I do water changes daily which equates to around 25% per week.
Before adding the water it's treated with either Seachem Prime or Fluval water conditioner.
The fish are fed on a mixture of dried flake and pellets and a variety of frozen blood worms etc.
My Ammonia, Nitrite are always zero and my nitrite is always 5ppm so in my opinion all good.

However, recently my pH, KH and GH have all increased and I am unsure why?

Here are some of my readings.......

	pH	KH	GH
24/01/2022	7.2	4	11
24/02/2022	7.5	4	10
19/03/2022	7.5	4.5	11
31/03/2022	7.5	5	10
09/05/2022	7.5	5	10
22/05/2022	7.5	5	15
26/06/2022	8	9.5	20

My local water authority (Northumbrian Water) state the following averages and ranges which is in line with my test of the tap water

	pH	KH	GH
NW	7.8 (7-8.4)	4.3(0.9-10.7)	5.9 (3.7-8.2)
TAP	7	5	6

So something is increasing the pH by around 1, the KH by around 5 and the GH by around 14 and the the only thing I have done in the past month is to add the coconut shells (pre boiled several times), remove 1 piece of bogwood and remove about 40 fry but the latter have subsequently been replaced with new ones .
Historically any changes in pH, KH or GH were minimal and always decreases not increases.
All of my fish appear to be fine with the exception of 1 of the gourami's which is bloated and the 3 adult platys which seem to hide a lot more than they used to even thought the smaller platys are fine.

So does anyone have any ideas?
I know the pH and GH are quite high for some of my fish but should I be overly concerned?
What is the most natural way to adjust if it's required?

As ever all help is much appreciated.
Mark.

 

[AmyKieran]

Hi all,

Hoping for some help with regards to recent changes in my water parameters....

Some info about my set up starting with a photo to set the scene .........

View attachment 162146

I have an established freshwater 4 foot 90g tank which contains:
2 Red Robin Honey Gouramis - approx. 2" in size.
10 Neon Tetras - 5 adult and 5 young.
7 Wag Tail Platys - 3 adults and 3 young - all now female to prevent further fry!
5 Panda Corys - Varying sizes, 1 of which was born in the tank and discovered when it was about 15mm long.
7 Dalmatian Mollys - 3 adults and 4 young - all now female to prevent further fry!
2 Bristle Nose Plecs - about 1" long and as yet unsexed.
2 Apple Snails - about 1" in size
And probably 30-40 Molly fry which will be going to a local fish shop once they are a bit bigger.

The substrate is a layer of aquatic sand varying from 0 to 1" and averaging at about 1/2 " in depth, I do not vacuum this at all.
I have several large of pieces of bogwood, 2 half coconut shells, plastic plants, a few oxygenators and several pieces of plastic pipe.
I have an internal filter with a UV light and oxygen input and at the other end of the tank a large external filter input which returns at surface level via a spray bar.
Both filters only contain sponge and ceramic media, no carbon or any pH / Hardness altering media.
I have 1 air pump to further agitate the water surface.
I do water changes daily which equates to around 25% per week.
Before adding the water it's treated with either Seachem Prime or Fluval water conditioner.
The fish are fed on a mixture of dried flake and pellets and a variety of frozen blood worms etc.
My Ammonia, Nitrite are always zero and my nitrite is always 5ppm so in my opinion all good.

However, recently my pH, KH and GH have all increased and I am unsure why?

Here are some of my readings.......

	pH	KH	GH
24/01/2022	7.2	4	11
24/02/2022	7.5	4	10
19/03/2022	7.5	4.5	11
31/03/2022	7.5	5	10
09/05/2022	7.5	5	10
22/05/2022	7.5	5	15
26/06/2022	8	9.5	20

My local water authority (Northumbrian Water) state the following averages and ranges which is in line with my test of the tap water

	pH	KH	GH
NW	7.8 (7-8.4)	4.3(0.9-10.7)	5.9 (3.7-8.2)
TAP	7	5	6

So something is increasing the pH by around 1, the KH by around 5 and the GH by around 14 and the the only thing I have done in the past month is to add the coconut shells (pre boiled several times), remove 1 piece of bogwood and remove about 40 fry but the latter have subsequently been replaced with new ones .
Historically any changes in pH, KH or GH were minimal and always decreases not increases.
All of my fish appear to be fine with the exception of 1 of the gourami's which is bloated and the 3 adult platys which seem to hide a lot more than they used to even thought the smaller platys are fine.

So does anyone have any ideas?
I know the pH and GH are quite high for some of my fish but should I be overly concerned?
What is the most natural way to adjust if it's required?

As ever all help is much appreciated.
Mark.

I’m also in County Durham under Northumbrian water. I haven’t had an increase that I know of. I’ll double check my tap water but my water is super soft

Kh - 3
Gh - 4
Ph - 7

 

[Byron]

Welcome to TFF.

I assume these numbers are in degrees, as dH...or are they mg/l (= ppm)? This is essential to know, as the GH increase if they are degrees is the more significant issue (and chances are the KH and pH would shift accordingly).

Another possibility is the water authority is deliberately increasing the GH, see if anything about this is on their website, or call them. It could also be they are obtaining the water from a different source which is more mineralized.

Something calcareous in the aquarium would increase GH/KH/pH. Is the substrate sand inert?

The above points come to mind first, and it is best to eliminate/confirm things so we know what we're dealing with.

Edit. Concerning the use of botanicals to soften water, this will only work if the GH/KH is low enough to allow it, otherwise they buffer and the botanicals will have little effect. Botanicals referring to almond or other dried leaves, peat, wood.

 

[Guyb93]

Hi all,

Hoping for some help with regards to recent changes in my water parameters....

Some info about my set up starting with a photo to set the scene .........

View attachment 162146

I have an established freshwater 4 foot 90g tank which contains:
2 Red Robin Honey Gouramis - approx. 2" in size.
10 Neon Tetras - 5 adult and 5 young.
7 Wag Tail Platys - 3 adults and 3 young - all now female to prevent further fry!
5 Panda Corys - Varying sizes, 1 of which was born in the tank and discovered when it was about 15mm long.
7 Dalmatian Mollys - 3 adults and 4 young - all now female to prevent further fry!
2 Bristle Nose Plecs - about 1" long and as yet unsexed.
2 Apple Snails - about 1" in size
And probably 30-40 Molly fry which will be going to a local fish shop once they are a bit bigger.

The substrate is a layer of aquatic sand varying from 0 to 1" and averaging at about 1/2 " in depth, I do not vacuum this at all.
I have several large of pieces of bogwood, 2 half coconut shells, plastic plants, a few oxygenators and several pieces of plastic pipe.
I have an internal filter with a UV light and oxygen input and at the other end of the tank a large external filter input which returns at surface level via a spray bar.
Both filters only contain sponge and ceramic media, no carbon or any pH / Hardness altering media.
I have 1 air pump to further agitate the water surface.
I do water changes daily which equates to around 25% per week.
Before adding the water it's treated with either Seachem Prime or Fluval water conditioner.
The fish are fed on a mixture of dried flake and pellets and a variety of frozen blood worms etc.
My Ammonia, Nitrite are always zero and my nitrite is always 5ppm so in my opinion all good.

However, recently my pH, KH and GH have all increased and I am unsure why?

Here are some of my readings.......

	pH	KH	GH
24/01/2022	7.2	4	11
24/02/2022	7.5	4	10
19/03/2022	7.5	4.5	11
31/03/2022	7.5	5	10
09/05/2022	7.5	5	10
22/05/2022	7.5	5	15
26/06/2022	8	9.5	20

My local water authority (Northumbrian Water) state the following averages and ranges which is in line with my test of the tap water

	pH	KH	GH
NW	7.8 (7-8.4)	4.3(0.9-10.7)	5.9 (3.7-8.2)
TAP	7	5	6

So something is increasing the pH by around 1, the KH by around 5 and the GH by around 14 and the the only thing I have done in the past month is to add the coconut shells (pre boiled several times), remove 1 piece of bogwood and remove about 40 fry but the latter have subsequently been replaced with new ones .
Historically any changes in pH, KH or GH were minimal and always decreases not increases.
All of my fish appear to be fine with the exception of 1 of the gourami's which is bloated and the 3 adult platys which seem to hide a lot more than they used to even thought the smaller platys are fine.

So does anyone have any ideas?
I know the pH and GH are quite high for some of my fish but should I be overly concerned?
What is the most natural way to adjust if it's required?

As ever all help is much appreciated.
Mark.

I find it harder to soften water than harden water , you could add botanicals like almond leaves or elder cones to try and soften it .
Unless you’re prepared to start a RO system I don’t know how you can consistently soften the water , maybe the change is due to less rain fall meaning water is not being diluted as much and hardening . Just a theory

 

[AmyKieran]

I find it harder to soften water than harden water , you could add botanicals like almond leaves or elder cones to try and soften it .
Unless you’re prepared to start a RO system I don’t know how you can consistently soften the water , maybe the change is due to less rain fall meaning water is not being diluted as much and hardening . Just a theory

Is there such a thing as a reverse reverse osmosis system? To harden water rather than soften it

 

[Essjay]

Your tap water shows much lower results than your tap water, so there's something in the tank causing the increase in there.

It's almost as if you swapped water sources with Lynnzer for a couple of weeks - his went from very hard to soft for a short period and now it's back to the usual hard. If yours did the reverse and you used very hard water for a few water changes, then your tap water returned to normal so that when you tested it, it was soft.....
Yes I know, very unlikely


Of course you could phone Northumbrian Water to ask if they changed your source temporarily in the last few weeks.

 

[sparkypenguin]

Thanks to all for the replies!

Welcome to TFF.

I assume these numbers are in degrees, as dH...or are they mg/l (= ppm)? This is essential to know, as the GH increase if they are degrees is the more significant issue (and chances are the KH and pH would shift accordingly).

Another possibility is the water authority is deliberately increasing the GH, see if anything about this is on their website, or call them. It could also be they are obtaining the water from a different source which is more mineralized.

Something calcareous in the aquarium would increase GH/KH/pH. Is the substrate sand inert?

The above points come to mind first, and it is best to eliminate/confirm things so we know what we're dealing with.

Edit. Concerning the use of botanicals to soften water, this will only work if the GH/KH is low enough to allow it, otherwise they buffer and the botanicals will have little effect. Botanicals referring to almond or other dried leaves, peat, wood.

The readings are in dH and in my OP I've provided test results from my tap today so unless they changed about a month ago and have changed back again it's probably not that. Also the last time I phoned them to discuss the incoming water I got fobbed off .

The sand is Unipac Aquarium Sand Natural Silver 20kg and according to the supplier is...
"Inert, this sand will not affect the pH of your aquarium and it has been prewashed to remove any contaminants. Aquarium Silver Sand is 150-250U so each grain is around 0.15 - 0.25 of a millimetre. Key Features: Comes pre-washed. Inert - won't affect your water pH. No dyes and no powder"
so should not be that.

 

[Guyb93]

Is there such a thing as a reverse reverse osmosis system? To harden water rather than soften it

I assume it’s the same , bring the water down to nothing so to say then add the minerals , I know a lot of saltwater setups use RO for that exact reason to make the water exactly how it’s needed , but for a fresh water set up I’d just get a 200l drum fill it with crush coral , shells anything you can find at the beach fill it with water and after a week it’s going to be liquid rock and you can repeat that every water change without messing around with minerals and RO

 

[sparkypenguin]

Your tap water shows much lower results than your tap water, so there's something in the tank causing the increase in there.

It's almost as if you swapped water sources with Lynnzer for a couple of weeks - his went from very hard to soft for a short period and now it's back to the usual hard. If yours did the reverse and you used very hard water for a few water changes, then your tap water returned to normal so that when you tested it, it was soft.....
Yes I know, very unlikely


Of course you could phone Northumbrian Water to ask if they changed your source temporarily in the last few weeks.

I cannot think of anything in the tank that would have changed it but I've listed everything in my OP and unless I'm missing something then ?!?!?!?

I think I will give NW a call tomorrow and hopefully will get through to someone helpful.
I'm also going to do a few extra water changes as I know my incoming is currently OK.

 

[StevenF]

How long has this tank been set up? From your data we now the parameters have been in creasing since january. Was there any change in stocking, water changes, products added to the water (dechlorinator, fertilizer) before January? Do you have PH, KH, Gh data from last year. You may have noticed it this may have been developing for a year or more.

Assuming there have been no changes in your tap water you could do larger water changes. 25% is not a lot and that could allow mineral buildup in the water. More fish would increase mineral buildup due to more fish waste if your stocking changed last year could be driving this.

While no obvious changes to tap water are known. You cannot exclude that a change has occurred. If the utility change the water source last year there may be changes in chlorination, sulfates, sodium and other minerals that would not show up in GH, KH, and PH tests at the tap but over time in your awarium they could start to affect GH, KH, and PH.

How old is the dogwood and coconut in your tank? these can leach acidic tannins or other organic acids into the water. That can reduce KH and PH but would not affect GH. If the tannins from thise items are running out you would see a PH and KH change while the GH would not change. Did you notice a KH PH change first and then noticed the GH?

An example is that I made a fertilizer batch and one mistake at that time didn't show up until about a year later. Minerals in the sediment in the substrate provided the nutrient that wasn't in the fertilizer batch I made and those minerals lasted about a year. Once the minerals in the substrate ran out the problem appeared.

 

[StevenF]

Is there such a thing as a reverse reverse osmosis system? To harden water rather than soften it

You can add a cartridge to the RI system what would put minerals back in the water. I don't recommend doing this for aquariums because the minerals the cartridge adds are selected for taste. They may not add the minerals plants and animals need in the correct ratios.

However your question made me realize that RO filters have 2 outputs. One is mineral rich water while the other is mineral poor water. the mineral poor water is stored for drinking while the mineral rich water is discarded. If some of the mineral rich water is saved it could be manually mixed with the pure water to reach a specific hardness desired while still maintaining the original mineral ballance that was pressent in the tap water. I haven't tried this so I don't know if there are any issues that are not apparent to me bow.

 

[sparkypenguin]

How long has this tank been set up? From your data we now the parameters have been in creasing since january. Was there any change in stocking, water changes, products added to the water (dechlorinator, fertilizer) before January. Do you have PH, KH, Gh data from last year. You may have noticed it this may have been developing for a year or more.

Thanks for reply.
The tank has been set up since around last November but I do not think the parameters started increasing until around the middle of May as any changes prior to this were only minimal and could be down to my interpretations of the sample colours v the chart.

How old is the dogwood and coconut in your tank? these can leach acidic tannins or other organic acids into the water. That can reduce KH and PH but would not affect GH. If the tannins from thise items are running out you would see a PH and KH change while the GH would not change. Did you notice a KH PH change first and then noticed the GH?

The wood is probably 20 years plus as it's from an old tank I used to have. The coconut was only put in about 2 months ago and was a fresh coconut that I used so if anything would possibly have brought the levels down slightly.

I'm going to call Water Authority tomorrow to see if they can cast any light on the issue and also gonna up my water changes to bring it down.

 

[AmyKieran]

I assume it’s the same , bring the water down to nothing so to say then add the minerals , I know a lot of saltwater setups use RO for that exact reason to make the water exactly how it’s needed , but for a fresh water set up I’d just get a 200l drum fill it with crush coral , shells anything you can find at the beach fill it with water and after a week it’s going to be liquid rock and you can repeat that every water change without messing around with minerals and RO

That might be a shout, may give it a go

 

[StevenF]

I don’t know how you can consistently soften the water , maybe the change is due to less rain fall meaning water is not being diluted as much and hardening . Just a theory.

In california many places get their water from steams in the winter. However once summer starts those streams dry up well water is used to make up. So seasonal GHchanges do happen in california and sometimes the GH change is dramatic.

 

[Colin_T]

There doesn't appear to be anything in the aquarium that should change the pH, GH and KH. So it's either the water supply has changed or the test kits are faulty.

Take a sample of tap water and tank water to a pet shop and get them to test it. Take your test kits too and test the same water at the same time. Write the results down when they do the tests. If you get different readings to the shop, then one of the test kits is dodgy.