# High kH a bad thing?



## Immortal1 (Feb 18, 2015)

Interesting - I have always assumed the KH would be the same as or less than the GH (silly me in my small world). So, given the research I did into my CA:Mg ratio issue, I am curious as to where this goes.

If I tested the CA level in the tank, and tested the GH level in the tank, I could predict the Mg level which resulted in me getting a better CA:Mg ratio. But, nothing was ever discussed how KH fit into that equation - if it even applied.

So, if 17dKH is very hard water, and 6dGH is not - how does *that* work??? 
Now I am very curious...


----------



## Quagulator (May 4, 2015)

Water softener strips all Ca and Mg  so 0 gH, but I boost with CaSO4 and MgSO4 to 5-6 gH


----------



## Immortal1 (Feb 18, 2015)

AH, thats whats happening. So, your tap water really is liquid concrete and you are looking for the best option...

Still curious where this goes


----------



## Quagulator (May 4, 2015)

Immortal1 said:


> AH, thats whats happening. So, your tap water really is liquid concrete and you are looking for the best option...
> 
> Still curious where this goes


Water directly out of tap, through softener:

kH - 17
gH - 0
pH - 7.6


Water at my old house (same township, 3km away, both groundwater sourced water) NO softener:

pH - 8.0-8.2
kH - 17-20
gH - ~20+? got bored after so many drops and shaking....


Using my RO mix to lower kH is getting awfully annoying, and I have to gH boost anyway, so really do I have to worry about high kH? like.... what is the benefit of people aiming/recommending kH values roughly 3-6? I would gH boost to 5/6 using the tap, just the kH would be ~ 17


----------



## MultiTankGuy (Jan 8, 2018)

Quag...

Everything I've read says if you keep a basic tank with fish from the local pet store and aren't trying to keep and breed rare fish species, you don't need to worry about the chemistry of your tap water. The chemistry simply needs to remain constant and the fish will adjust. 

I just remove and replace most of the water in my tanks every week or so and don't fret over the pH, hardness or any of the chemistry stuff. It's been my experience that knowing the chemistry of the tap isn't a requirement for keeping a clean tank with healthy fish. My tanks have been running for years and I've never had a tank problem.

M


----------



## jeffkrol (Jun 5, 2013)

> Carbonate hardness, is a measure of the water hardness caused by the presence of carbonate (CO2− 3) and bicarbonate (HCO− 3) anions. Carbonate hardness is usually expressed either in degrees KH (dKH) (from the German "Karbonathärte"), or in parts per million calcium carbonate ( ppm CaCO.


Need to find where the carbonates are coming from...
Substrate/decorations are the usual source.

CO2 injection will increase it as well:
https://www.thekrib.com/Plants/CO2/


> Carbonate is formed by the binding of free carbon dioxide (CO2) to calcium and or magnesium.


It gets muddy:
https://www.thekrib.com/Plants/CO2/hardness-larryfrank.html

Oh and see multitank guy as well..


----------



## tamsin (Jan 12, 2011)

Can you bypass the softener? Then just use a small amount of tap. Or just use RO remineralised with no tap.


----------



## Quagulator (May 4, 2015)

Just tested straight from the tap, API kits, results are:

kH - 15
gH - 0
pH - 7.6
pH high range - 7.4

@jeffkrol,

Thanks, I understand _what_ kH is referring to. It's impossible for me to tell where the carbonates are coming from, it's also impossible for them to be coming from decor/substrate as the values are straight from my tap, never seen the tank 

@MultiTankGuy,

While I'll agree with your statement for the most part, I've toyed around with less than favorable water parameters before, and the whole "6.0-8.2 pH is fine, fish will adjust" is not all applicable in my experience. The farther you stay away from the extremes (mostly talking high 8.0+ pH here) the better off I am with plants and fish. When I was running un-softened, straight tap at my old house, only certain plants could thrive, and many fish never seemed to do well despite being otherwise healthy, they would just wither away with time. Some would do very well, others would die in a week, some would live for years but never seem to truly thrive. I was discussing this with some other forum members with similar pH and water chemistry, and we tended to agree on that aspect... 

Plus, my tap has 0 Ca and 0 Mg so plants, shrimp, snails etc. will certainly be deficient unless I play with my chemistry. 


@tamsin

There is no way of bypassing the softener, and if so, I would be in the same scenario? I would have to mix mostly RO to a little bit of tap, exactly what I'm doing now.... Larger water changes are getting to be a pain. Space and time are the biggest drawbacks. Unless I set up a float valve system that will shut the RO off when my holding tote is full... But again, space is not a luxury in my home at the moment. 


@ Everyone 

What I'm really asking is: Is there any drawbacks of a high kH in a planted tank?


----------



## jeffkrol (Jun 5, 2013)

That is like seltzer water.. After the water "sits" does the Kh change?

Sorry so used to dealing w/ the other end (high Gh, low Kh) can't say much..


----------



## Quagulator (May 4, 2015)

jeffkrol said:


> That is like seltzer water.. After the water "sits" does the Kh change?
> 
> Sorry so used to dealing w/ the other end (high Gh, low Kh) can't say much..


I'm not sure about letting it sit.... I'll let some sit for a day and test...

I figured not many have experience with high kH and not gH as well...


----------



## PlantedRich (Jul 21, 2010)

I run very much at the other end of things on water as I am in the Central states where much of the ground lays over a vast layer of limestone. That makes any ground water very hard, alkaline. My thoughts are that it may give me some trouble with some plants and some fish but then I am pretty used to it being some trouble at most times. Just part of the game? 
Does it bother the fish? Some as I see platies in a CO2 enriched tank are not breeding like fleas. But the question is not what to do but do I really want those little buggers to deal with or is it just their problem. I got them by accident when swapping tanks and I will keep them for now but if they do not breed, it's fine with me. I like big fish and all the big fish seem fine with the water. I've bred angels, rainbow cichlids and mostly I breed African cichlids so if there is a problem with the fish and water, I don't see it in the fish I do want. 
Plants? Hard to say as I often find a plant here and there that does not prosper but then the question becomes not so much what the water is doing but what I might be doing. Most of those plants that die get replaced with something that doesn't die. 
Maybe more algae than I would like? Yes, that is true but whether it is due to the water or me? I'm very tolerant of things that are too much work/worry to change! 
When first keeping fish, I did lots of sweating study and work to keep it all just right and lots of fish died. Now I study less and fish live much longer! 
I would try to get straight, untreated water from an outside faucet or cut in a tap and gradually begin to move the tanks to hard alkaline water and stop the fight with nature as there are certainly fish and plants living in every type of water. The local springs come straight out of limestone and there are fish and plants in all of them. 
A look at Aquarena Springs for example:
https://www.google.com/search?q=Aqu...UICygC&biw=1280&bih=595#imgrc=MCvAbmOF45RxVM:


----------



## jeffkrol (Jun 5, 2013)

Brief analysis.. high Kh isn't a problem.. zero Gh is.. Need to supplement (as you are doing) Ca and Mg.

I guess one surprising thing is the Ph being "low" w/ that much carbonate..


----------



## Quagulator (May 4, 2015)

Once I move the last pair of fish out of the tank, I think I'll go ahead and start going straight tap and boost gH to my current levels....
@PlantedRich

You aren't at the opposite side in terms of water source as me. Un-softened water in my location is very alkaline, and just like you, some fish and some plants just could never do well. Now that I make my own water chemistry, (much softer) all fish do much better (not talking Africans or other harder water fish), and the plants I am successfully keeping has grown dramatically. 

And again, I have no access to un-softened water in my household. The main water source comes in through the floor in my basement straight into the softener. Every single tap, faucet or any source of water all goes through the softener. Want to water the grass or top up the pond? softened water, want to wash your car? softened water.... hence my struggle....
@jeffkrol

I've been struggling in my mind too as to why the pH seems "low" compared to the higher kH. It's not like I haven't grown plants in water with the kH being so high... but the gH was also equal/greater the kH... so I've never had experience with lower, normal gH and higher kH, only high kH + gH, or "normal" kH + gH. This said, I can't predict if the higher kH will hinder certain plants I couldn't grow in the past, or if that is related to mega high gH.


----------



## jeffkrol (Jun 5, 2013)

Hmmm.. Kind of missed that part.. Your Ca and Mg is being replaced by Na or K...thus low Gh.. Won't remove carbonates..


----------



## Greggz (May 19, 2008)

I am also on a well going through a softener. Before I went full RO, I used straight tap water.

So high KH no GH. Dosed to bring up general hardness. High TDS due to salt exchange. 

And all that being said, in reality you can have a very nice tank with those parameters. You just need to find plants that like what you are providing. Takes some trial and error. That is what I did for a quite awhile. 

But there is only so far that that will get you. Some more sensitive species will not have much of a chance. In general, there are more plants that prefer softer rather than harder water, and prefer low TDS to high. I got to a point to where I wanted to have a better chance with everything, so I went to full RO. 

So it depends on where you want to take things. If you decide you want to use more RO, maybe you could take some time upfront to automate the process as much as possible. That way it would be less of a pain.

As an example, I set up my RO so it pumps up from the basement, comes right out of the wall into the tank. One switch and it fills. Same process for draining, pumped into pipe in the wall right down to the basement drain. One of the best things I ever did.

But either way, you can be successful, in my experience just to a varying degree.


----------



## Edward (Apr 11, 2005)

You need to look at it this way, if the chemical used to recharge the house softener is the usual NaCl sodium chloride then Ca and Mg are replaced by Na sodium. This Na forms Na2CO3 sodium carbonate which is an alkaline pH buffer. 

Basically, the water out of the softener is normal high pH water; 
without Ca
without Mg
and
with added Na
and
with added alkaline pH buffer

So, Ca and Mg need to be added back in form other than CaCO3 and MgCO3 because they increase KH. This water doesn’t need more KH. Also other than CaCl2 and MgCl2 because there is already Cl leaked from the NaCl regeneration chemical. CaSO4 and MgSO4 in the recipe can do it, also CaNO3.

Because pre-softener GH is over 20 dGH there is high level of Na in the after-softener water. This is closer to brackish water parameters with high osmotic pressure and high TDS. To balance this out, higher levels of macronutrients NO3, PO4, K, Ca, and Mg are needed. Especially higher PO4 is needed in high pH water.

Additionally, due to high pH, most trace elements are less available to plants. Therefore, need to add more than usual.


----------



## Quagulator (May 4, 2015)

Edward said:


> You need to look at it this way, if the chemical used to recharge the house softener is the usual NaCl sodium chloride then Ca and Mg are replaced by Na sodium. This Na forms Na2CO3 sodium carbonate which is an alkaline pH buffer.
> 
> Basically, the water out of the softener is normal high pH water;
> without Ca
> ...


7.4 is considered high pH???

Good info regardless, thanks for that!


----------



## Edward (Apr 11, 2005)

Water 17 dKH without CO2 and other acids should be at 8 pH. Also water at your previous house tested 8 pH. So, the dKH is more accurate at this point, not the pH reading.


----------



## Quagulator (May 4, 2015)

Edward said:


> Water 17 dKH without CO2 and other acids should be at 8 pH. Also water at your previous house tested 8 pH. So, the dKH is more accurate at this point, not the pH reading.


Well now I'm totally confused, no where near 8 pH as per API kits... I'll check the degassed tap water tomorrow....


----------



## Surf (Jun 13, 2017)

> That is like seltzer water.. After the water "sits" does the Kh change?
> 
> Sorry so used to dealing w/ the other end (high Gh, low Kh) can't say much..


The KH will not change after it sits. GH is a measure of calcium and magnesium the water. These may be in the form of sulfates, chlorides, nitrate, or carbonates. GH will detect calcium and magnesium in whatever form they are in. 

KH on the other hand is measure of carbonate CO3 attached to another atom. So that KH test will detect Potassium bicarbonate, and sodium bicarbonate while the GH test will not. Two other common carbonates are calcium carbonate and magnesium carbonate. And the GH and KH will detect these. Another thing to note is that the KH test will not detect CO2.


----------



## Greggz (May 19, 2008)

Quagulator said:


> 7.4 is considered high pH???
> 
> Good info regardless, thanks for that!


Boy I missed that too.

If your KH is truly 17, there is no way your degassed pH is 7.4.

Are you testing the water right out of the tap? The reason I ask is that well water usually has quite a bit of CO2 in it. When I was using my well water, my KH was about 20, and my degassed pH was about 8.2.

Right out of the tap pH was 7.6. Your degassed value might be quite different. 

And by the way, I would not trust the API pH kit. I have tested them against a calibrated probe, and many times it is not even close. I would not trust them at all for our purposes.


----------



## Chlorophile (Aug 2, 2011)

Greggz said:


> Boy I missed that too.
> 
> If your KH is truly 17, there is no way your degassed pH is 7.4.
> 
> ...


Agreed, my pure RO water in my holding tank measures a 7.1 to 7.2 from my pH pen, thats with 0kH... it's covered and I don't think it has any dissolved gasses in it as I don't see the typical bubble-fest during water changes that I used to with tap-water. 
Not sure what the equilibrium for co2 is in my home but if I can guess on the numbers alone I must have like 1ppm co2 in my holding tank.


----------



## Quagulator (May 4, 2015)

Degassed tap water:

pH - 7.6
pH High Range - 7.4-7.8 (hard to tell color)
kH - 14

TDS meter and pH meter are on the way with amazon prime.... should show more accuracy


----------



## Greggz (May 19, 2008)

Quagulator said:


> Degassed tap water:
> 
> pH - 7.6
> pH High Range - 7.4-7.8 (hard to tell color)
> ...


How did you degas the water? Just leave it out? Or put an air stone in it?

I ask because at KH 14 your pH should still be around 8.0 or so. 

Will be interesting to see what the pH meter reading is. Did you get some calibration fluid for it?


----------



## Quagulator (May 4, 2015)

Greggz said:


> How did you degas the water? Just leave it out? Or put an air stone in it?
> 
> I ask because at KH 14 your pH should still be around 8.0 or so.
> 
> Will be interesting to see what the pH meter reading is. Did you get some calibration fluid for it?


Yep, it comes with calibration fluid as far as I can tell. 

Tested my pond fish holding water, straight tap water as well, airstone, canister filter:

pH - 8.0
kH - 14

I guess those results give me my answer....


----------



## Greggz (May 19, 2008)

Quagulator said:


> Yep, it comes with calibration fluid as far as I can tell.
> 
> Tested my pond fish holding water, straight tap water as well, airstone, canister filter:
> 
> ...


Yeah that sounds about right now. If you just set a glass of water out to degas, the pH can keep rising for as many as three days. 

Even when I use an air stone to degas, I just let it run over night to be sure.

It is important to get it right, as we base our pH drop off that number. 

But back to your original thoughts, my numbers were worse than yours, and I still managed to get along O.K. for a long time (with certain plants). So it will be interesting to see how things go. 

And nice recent update in your journal. 

Also will be interesting to see what your TDS is. Mine out of the tap (softened well water) is around 500.


----------



## Quagulator (May 4, 2015)

Greggz said:


> Yeah that sounds about right now. If you just set a glass of water out to degas, the pH can keep rising for as many as three days.
> 
> 
> 
> ...




Thanks, I’m interested as well, my guess is it’s fairly high... tds that is. 

As for the parameters discussed here, it’s for a low/medium tech 90 gallon I’m working on overhauling, and using the same mix as I am in my journal is getting pretty annoying. The tank in my journal will continue using my tap:RO mix. 

Maybe for the bigger tank I’ll go ahead and go half and half, see if there is any difference . Should make larger water changes a little easier but keep decent parameters... ~7.5 pH and 7-8 kH. I’ll still have to gH boost, but less playing around with filling and storing RO. 


Sent from my iPhone using Tapatalk


----------



## Greggz (May 19, 2008)

Quagulator said:


> Thanks, I’m interested as well, my guess is it’s fairly high... tds that is.
> 
> As for the parameters discussed here, it’s for a low/medium tech 90 gallon I’m working on overhauling, and using the same mix as I am in my journal is getting pretty annoying. The tank in my journal will continue using my tap:RO mix.
> 
> ...


If I were going low/medium tech, I wouldn't bother with the RO. Many lower light plants are pretty tough regarding parameters. You would be limited with choice of stems, but could easily do a mix of crypts, swords, ferns, etc and I doubt they would mind your tap at all.

Throw a few Bows in there and it will provide some nice color!:grin2:


----------



## Quagulator (May 4, 2015)

Greggz said:


> If I were going low/medium tech, I wouldn't bother with the RO. Many lower light plants are pretty tough regarding parameters. You would be limited with choice of stems, but could easily do a mix of crypts, swords, ferns, etc and I doubt they would mind your tap at all.
> 
> Throw a few Bows in there and it will provide some nice color!:grin2:


Ahaha I actually sold off some bows, heartbreaking I know, I have my reasons though.... on the other hand my LFS has some drop dead gorgeous Melanotaenia Herbertaxelrodi .... but, that ship has sailed, I think the plan with the bigger tank is to do ~100 nano fish like chili rasbora, species only vibe, we will see. 

But, I still have an itch to go after high tech, I mean, all I need is another CO2 setup and 1 more dual bulb T5 fixture and I'm set for high tech high light....


----------



## Greggz (May 19, 2008)

Quagulator said:


> But, I still have an itch to go after high tech, I mean, all I need is another CO2 setup and 1 more dual bulb T5 fixture and I'm set for high tech high light....


LOL, you've got the bug.....what was I thinking?

That's how I got started......one thing led to another......and well I've got to warn you it never stops!!:wink2:


----------



## Quagulator (May 4, 2015)

God my TDS meter and pH meter, I din't have time on my lunch hour to calibrate the pH meter, so the various tds are as follows:

Straight fresh tap - 420 ppm
Degassed tap - 417 ppm 
Several year old established 90 gallon - 325 ppm
1 year old 5 gallon - 280 ppm
1 month old 30 gallon - 417ppm (must be EI dosing, Ca and Mg dosing???)


----------

