# High KH, Low GH from water softener



## banderbe (Nov 17, 2005)

My KH is 20 dKH and my GH is very low (don't remember the figure now).

This is due to the water softener we have which replaces the calcium with sodium..

I have seen some people say that elevated sodium levels can be bad for planted tanks, but how can I measure my sodium level?

What can I do to make sure my water is going to be good for plants?

I saw this product called Equilibrium (http://www.seachem.com/products/product_pages/Equilbrium.html that will raise the GH.

Does anyone else here use water from a water softener in their planted tank?

Any advice, anecdotal or otherwise is appreciated.


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## Raul-7 (Feb 4, 2004)

The water softener replaces both Mg and Ca ions with Na ions. I doubt it has an affect on the kH (CO3) of water. I do not know how you can test for Na in your water; maybe a hydrometer will work? 

Equilibrium is great for raising gH; not only that but it supplies a good amount of K and Fe. But first fix the Na problem in your water; would you be willing to invest into an RO unit?


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## Pieter (Jul 3, 2005)

banderbe said:


> My KH is 20 dKH and my GH is very low (don't remember the figure now).
> 
> This is due to the water softener we have which replaces the calcium with sodium..
> 
> ...


Wouldn't it be possible to take water before it goes through the softener.
If possible I would rather use that water then the water that comes out of the softener. You can grow a lot of plants in very hard water so taht is the way I would go. At least at first. Maybe later invest in an RO unit. But I gave up on that. With that high of a KH you will have a lot of wast water from the unit.
Maybe ask your neighbours for some water and test that for the GH. This will give you an idea of how much Ca and Mg was replaced by Na. Most certainly your water after it is softened will have very high levels of Na, wich is not very good.

Pieter


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## banderbe (Nov 17, 2005)

Raul-7 said:


> The water softener replaces both Mg and Ca ions with Na ions. I doubt it has an affect on the kH (CO3) of water. I do not know how you can test for Na in your water; maybe a hydrometer will work?
> 
> Equilibrium is great for raising gH; not only that but it supplies a good amount of K and Fe. But first fix the Na problem in your water; would you be willing to invest into an RO unit?


Eventually I am going to purchase an R/O unit, but that won't be for many months.

I may be able to use potassium chloride instead in my water softener to use K instead of Na to soften water.. I'm currently investigating this..


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## banderbe (Nov 17, 2005)

Pieter said:


> Wouldn't it be possible to take water before it goes through the softener.
> If possible I would rather use that water then the water that comes out of the softener. You can grow a lot of plants in very hard water so taht is the way I would go. At least at first. Maybe later invest in an RO unit. But I gave up on that. With that high of a KH you will have a lot of wast water from the unit.
> Maybe ask your neighbours for some water and test that for the GH. This will give you an idea of how much Ca and Mg was replaced by Na. Most certainly your water after it is softened will have very high levels of Na, wich is not very good.
> 
> Pieter


I was also thinking of this option, possibly installing some faucet valve in my utility closet to allow me to get water before it enters the softener when I need to, but the problem here is that then I get cold water since the water heater heats the softened water. I can't very well put cold water into my tank, and putting it in some sort of resevoir to warm up to room temp in the mean time isn't something I'm willing to mess with. I want a direct hook up to the water so I can pump it right into my tank like I do now from the sink. *shrugs*

I am going to keep thinking about this.


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## TWood (Dec 9, 2004)

banderbe said:


> I may be able to use potassium chloride instead in my water softener to use K instead of Na to soften water.. I'm currently investigating this..


Yeah, I considered this as well, but it costs three or four times as much per bag, here anyway. Still, if you don't go through as much water softening salt as we do, it might be worth it.

TW


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## Raul-7 (Feb 4, 2004)

You mean change the resin from being loaded with Na ions to be loaded with K ions? As I understand, water softners use a zeolite resin loaded with Na ions; as the water passess though the zeolite the Na ions interchange with the Ca and Mg ions.


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## TWood (Dec 9, 2004)

Yes, K+ exchanges instead of Na. It's intended for use with septic systems that are sensitive to sodium. I just loaded 6 - forty pound bags into ours - $3.90 a bag for sodium, $9.80 a bag for potassium, so not as high as I remembered, but still substantially more.

TW


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## jrIL (Apr 23, 2005)

I have hard water as well. KH at 17 to 22. I throw the bypass valve on the water softner when I fill the tank from the cold water faucet. I never use warm. I just mix the cold in and only see around a 4 degree drop in temp when doing a 40 to 50% water change. It has never caused any trouble and I have never seen any signs of distress in the fish or plants.


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## HeyPK (Jan 23, 2004)

The problem with softened water is that the KH is all due to sodium bicarbonate, which is alkaline. The KH is high, and the GH is close to zero. Hard water has calcium and magnesium bicarbonates, which are less alkaline and also supply the needed nutrients, calcium and magnesium for your plants. When I used the local well water here, which is softened by some sort of underground natural process so that it has no Ca or Mg, but plenty of sodium bicarbonate, I used to see calcium deficiency in my plants frequently. The tap water comes out of the tap with a pH of 8.6. I switched over to collecting rain water and adding ground limestone or just lime to get the needed calcium. ground limestone dissolves a lot more readily in rain water than it does in the alkaline tap water here.


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## Raithan Ellis (Nov 13, 2005)

banderbe said:


> My KH is 20 dKH and my GH is very low (don't remember the figure now).
> 
> This is due to the water softener we have which replaces the calcium with sodium..
> 
> ...


We have the same setup here, sodium ion exchange softener using rock salt... frankly don't bother with the potassium chloride, the cost really isn't worth it IME.

I literally just finished my monthly tests of the well water from our cold bypass (which I use to fill my tanks), softened water and tank water.

The KH from the well water was a straight 5.0 dGH, the KH from the softened water was borderline 5.0-5.5 dGH, both share the same pH at 7.0-7.2. So, I really don't think it will affect your KH much if any at all. Wish I could tell you my GH but I just finished shooting an e-mail off to AP asking if there are any problems with the lot no. of my GH kit.

As per my experience with plants, I never had a problem using softened water in any of my tanks (I've read alot of opinions stating the contrary, but my experience says it's perfectly fine)... frankly I still would use the softened water if I could (since I can adjust water temps that way, hot water heater doesn't run on the bypass), but I don't have a hose hookup down here in the basement for it. So... I'm stuck with using the cold water bypass... and frankly it really isn't an issue even with larger water changes (30%-50%). I might notice the temps drop by around 5-6 dF at maximum. Doesn't seem to bother the fish or plants any, actually the fish seem to like it.

Don't worry about everything you read, experience is the best teacher.

P.S. A hydrometer won't work for testing Na levels in softened water. I really don't think it's even worth the effort to try and figure out IMHO.


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## awohld (Dec 11, 2005)

HeyPK said:


> I switched over to collecting rain water and adding ground limestone or just lime to get the needed calcium. ground limestone dissolves a lot more readily in rain water than it does in the alkaline tap water here.


How is using rain water working out for you? How do you treat it?


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