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Discussion Starter #1
Is there a draw back to using water with high kH?

Tap water with gH boost:
kH - 17
gH - 6
pH - 7.6

I'm hoping to start increasing the sizes of my water changes, and using my RO unit is getting to be a pain when compared to going straight tap.

Current RO:Tap mix:

kH - 6
gH - 6
pH - 7.4

So the only difference really is a higher kH.
 

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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...



 

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Discussion Starter #3
Water softener strips all Ca and Mg ;) so 0 gH, but I boost with CaSO4 and MgSO4 to 5-6 gH
 

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Discussion Starter #5
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
 

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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
 

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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.. ;)
 

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

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Discussion Starter #9
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?
 

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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..
 

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Discussion Starter #11
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...
 

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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:
 

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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..
 

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Discussion Starter #14
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.
 

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

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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.
 

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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.
 

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Discussion Starter #18
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.
7.4 is considered high pH???

Good info regardless, thanks for that!
 

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Discussion Starter #20
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....
 
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