# Whole House Water Softeners



## Quizcat (Dec 21, 2014)

I have been reading some conflicting information that whole house mechanical water softeners that use an internal salt bath mechanism to soften water isn't good for aquariums. Yet, I also regularly read in the forums where many fish keepers add some aquarium salt to their freshwater tanks to condition their water, and many defend that practice pretty strongly from many years of having done so.

It would seem to me that the very minute residue of salt, the most of which is pumped down the drain after use within the water softener, would be a significantly less amount of salt than would be added to a tank by those that subscribe to the idea that adding salt to their aquariums is actually quite good for water conditioning. 

If adding salt is a beneficial common practice, which is definitely seems to be the case if you survey the forums, I can't see how using a water softener would be detrimental, provided you add a small token amount of essential minerals back into the tank that may have been extracted from the water during the water softening process. 

The only exception to this might be whether the salt residue would negatively effect certain plants. In my case, I have a low tech tank, just recently added some Anubias, and plan to add some water lettuce or frog bit on top to soak up Nitrates in the near future. 

Anybody have any experience using mechanically softened water to fill their tanks or when doing top-offs?


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## klibs (May 1, 2014)

Who are these people that add salt to their freshwater tanks on a regular basis? Freshwater fish (unless brackish) do not like salt. Freshwater plants do not like salt. What benefits would this provide? The only times I hear people add salt to their freshwater tanks is as medication to combat stuff like parasites.

Having said that I have no idea about mechanically softened water / if it could be harmful. Out of curiosity are you looking to soften your water in the first place?


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## Quizcat (Dec 21, 2014)

*Salt in the Water Softener...*

Well, yeah, I have one of these soft water systems, and I recently started to keep up with replenishing the salt in the reservior. Sometimes I neglect replenishing the salt in the system, and the water softener just stops working. When that happens, my tap water reverts back to being very hard, well over 450ppm GH hardness. 

There are times that I am neglectful at replenishing the salt, and there are times that I've kept up with it. I just use tap water for water changes and top offs, sometimes softened, and sometimes not. I've never noticed any adverse effect from the tap water in the past, softened or not. 

But now I've added a couple of German Blue Rams, and I wonder if over time, they might be adverse to it. I've had some glow fish, and corydoras over the last few years, and they seem fine either way with my tap water, softened or not. 

Since I started keeping up with the salt replenishment lately, it occurred to me to check into whether the softener might be adversely affecting the tank water when I do water changes and top-offs. 

So, I simply searched various internet forums to see what people had to say. A surprising number of fish keepers said they dose a very small measure of salt to their fresh water aquariums when they do water changes. And, they weren't doing it as medications, but as a routine practice during water changes. If you Google it, you'll see what I mean. And, some of them are old timers too, with many years of experience in the hobby. In fact, they swear by it! 

I know what you mean by your skepticism, and I'm not advocating it. But, some of them claimed that they've been intentionally doing it for 30 years with no adverse effects on their fish, and that they believe it results in positive effects in doing so. 

Plants? Well, that might be a different thing. But, some of them did claim to have plants, and they claimed to have experienced no adverse effects. I'm sure it depends on the type of plants one has, assuming that what they reported is true.

There were also numbers of fish keepers that advised against adding small amounts of salt to a tank, and against using water from a soft water system, claiming that the residue from the salt would be detrimental to the tank. 

Personally, I can't see it, and especially if what some of the fish keepers that use small amounts of salt in their tanks report, but also because you can't even taste the salt when I draw softened water from my tap.

But, because I find that members in this forum seem to be generally more informed compared to some other forums, I am curious what opinions the members of this forum may have with regard to using softened tap water where salt is the cleaning agent used by the system to keep the resin collector clean.





klibs said:


> Who are these people that add salt to their freshwater tanks on a regular basis? Freshwater fish (unless brackish) do not like salt. Freshwater plants do not like salt. What benefits would this provide? The only times I hear people add salt to their freshwater tanks is as medication to combat stuff like parasites.
> 
> Having said that I have no idea about mechanically softened water / if it could be harmful. Out of curiosity are you looking to soften your water in the first place?


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## Greggz (May 19, 2008)

Quizcat said:


> Anybody have any experience using mechanically softened water to fill their tanks or when doing top-offs?


I use well water that runs through a softener. It comes out at KH about 18, pH at 8.2, and GH at zero.

It also has high TDS, about 650ppm out of the tap. In general, a toxic soup that no one would recommend.

However, somehow I manage to do O.K. Fish thrive, and I'm successful with certain plants. Notice I said certain. There are some I just can't grow, and some that flourish. It's really just a process of trial and error. Is it ideal? Probably not, but very doable. 

That being said, I have considered for some time going with a RO water system, and just may someday. In the meantime, things overall are pretty darn good.

Now as to the adding of salt, this was very popular back in the 80's/90's. There was a theory that a bit of salt would create a thicker slime coat, and make fish more resistant to picking up disease. Could have been a bunch of hooey, but who knows. Sounds like you are hearing from some old timers (no offence, I'm one too) who have been doing it all these years. I used to know a guy pretty well who owned a LFS, and he put a little salt in all his fresh water tanks for decades. 

Personally I think there are no real benefits, and these same folks would do as well or better without it. And I seriously doubt any of these folks have planted tanks. Salt and the planted tank are not good companions.

And remember to keep in mind that no two tanks are exactly the same. Results can and do vary, and no one can give you an absolute answer on what will or what won't work in your tank.

A large part of this hobby can only be learned by trial and error. Over time you will find out what works in YOUR tank, so let your experience be your guide.


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## rzn7z7 (Aug 17, 2013)

Agreed, I think the recommendation towards adding some salt to the aquarium was for medicinal purposes and am pretty sure it was for fish-only tanks

In my past experience using softened water in a planted tank you could keep some hearty plants but the plants I wanted to keep, mostly crypts, just melted. It's been too long to recall what those hearty plants were. For awhile to keep crypts I toted water from my parents' house who were on city water and kept it in a reservoir....what a pain

Today our house has a water softener but I use 100% RODI and reconstitute it with GH and KH boosters....highly recommended


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## Quizcat (Dec 21, 2014)

Sure, some do use it for medicinal purposes, but I think most that did it routinely were adding it as a preventative measure.

I think RO/DI is the best option, but for me it's just too much of a hassle. 



rzn7z7 said:


> Agreed, I think the recommendation towards adding some salt to the aquarium was for medicinal purposes and am pretty sure it was for fish-only tanks.
> 
> Today our house has a water softener but I use 100% RODI and reconstitute it with GH and KH boosters....highly recommended


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## petromotion (Feb 1, 2017)

What about anyone with a non-salt water softener? Something like the NuvoH2O system. It uses a citrus based filter not salt. I have been debating this for my house and don't know how it would effect the water.


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## PlantedRich (Jul 21, 2010)

When speaking of "mechanically softened but using salt, I might guess that it is more correct to call it an ion exchange softener. It is done mechanically but the process is to replace calcium and MG ions with sodium ions and that is where the salt is used. You are correct that most of the salt is not left in the water but used as a brine rinse for the softener media and then flushed down the drain. You need to keep replacing the salt because the salt keep getting flushed down the drain. However there is obviously SOME salt left after the rinse, just as there is some soap left on your plate after washing and rinsing. The amount of salt the normal person takes in from drinking softened water is often compared to what one finds in a single slice of white bread. So if you are on a strict diet to avoid salt, potassium is suggested as the better way to soften the water. 
But the salt in soft water is not the problem as I see it. I use softened water to feed the irrigation on one side of my house in Texas and it doesn't bother the grass at all. There are plants which thrive in salty environments and there are those who will not. The air within a couple miles of the coast is often more salty than softened water. Think Florida? 

I find the softened water is lacking in all the minerals that I need so I have a choice of using it and fighting to add those back or finding a way to tap into the line before it goes to the softener. Adding a tap was far easier for me. In Texas may softener is just through the wall from the fish room so punching a whole was ideal. 
If you are anywhere in the West County area, you definitely will need the softener but , maybe looking at how it is plumbed would show an easy way to tap in before the softener?
At the top of the softener, there is likely to be a bypass with possibly arrows showing which is going in and out.


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## maxhrbal (Mar 19, 2016)

I have an in home softener and do just fine. I'm not going to turn it off for the sake of my fish, though I do agree that it should be avoided if possible. But again, I've never heard anyone say "my water softener ruined my fish tank!" LOL. A lot of people add salt to their aquariums. I don't. It's also another hassle and you h e to be careful. Adding salt just adds too many more variables to the mix and is probably unnecessary unless treating for something. Some fish and plants are particularly more sensitive than others. I would generally recommend not adding salt to aquariums. As for softeners, it's a bit different and doesn't add as much as if you were to add aquarium salt (to put it simply and vaguely) 


Sent from my iPhone using Tapatalk


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## jeanjean (Jun 6, 2019)

klibs said:


> Who are these people that add salt to their freshwater tanks on a regular basis? Freshwater fish (unless brackish) do not like salt. Freshwater plants do not like salt. What benefits would this provide? The only times I hear people add salt to their freshwater tanks is as medication to combat stuff like parasites.
> 
> Having said that I have no idea about mechanically softened water / if it could be harmful. Out of curiosity are you looking to soften your water in the first place?


I agree with your opinion. First, the main purpose of using a water softener is to soften hard water and solve the water quality problem of domestic water. Second, salt is not friendly to plants. If you need to water your yard, you'd better use water from other sources.


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## Leeatl (Aug 8, 2015)

I use softened water and have for years with no ill effects on fish or plants , but my water is soft to begin with . I got the softener by a very tricky sales tactic that I won't get into , but I do like the carbon canister that takes out the chlorine/chloramine and other stuff . My water has a hardness of 1 according to the water report , so I don't think there is much salt in the finished product . I could be wrong .


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## mboley (Jan 26, 2018)

I went this route for a little while. I have a whole house softener using potassium salt with the addition carbon filter. I think it's safe to say that the residual potassium salt in the water is better than residual sodium for a planted aquarium. And I can't imagine the amount of salt a hobbiest typically might add is anywhere near what is left over after softening with sodium. 

I had my softened water tested for potassium. It was 210ppm, so I decided to cut it with 50% RO. I was just being lazy about going 100% RO. But I didn't feel good about the leftover salts in the water. My TDS was 150-200 higher than my regular tap water. That increased TDS is from the residual salts in the water, either potassium or sodium. I just didn't feel comfortable with it after I started losing fish one by one over a six month period. I was also pushing CO2 at the time but thought the one by one deaths were odd.

So there is enough residual salts after softening to raise TDS substantially. Hence, there is something in the water, harmless or not, I dont know.

I've since gone to 100% RO and like knowing there's nothing extra in the water . I think softened water is an unknown.


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## AcidGambit (Aug 30, 2018)

Softened water caused me to waste close to a year with my high-tech tank, wondering why many of my plants would simply waste away. Also, one thing to note is that some whole-house water softeners are plumbed for the entire house, whereas others are only plumbed to the hot water outlets. The result is that some of the folks that have had success might have not been introducing nearly as much salt as others (because they were using mostly cold water, which doesn't contain salt). Unfortunately for me, all of my outlets are plumbed to the water softener and there is no bypass. I'm in the process of switching over to RODI water now.


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## protege (Jun 12, 2019)

I am curious about using RODI for freshwater. I was in the reefkeeping world for a long time and recently switched to freshwater. In marine tanks, I used RODI so I could control all mineral aspects of the water and ensure the proper balance of for our corals. However, I wonder about the freshwater use. Typically, I just use tapwater with Prime and enjoy my planted tank. I do not test for every mineral, but for those that do, are you dosing other minerals? If so, why? Please forgive my ignorance, I have been reading, but this topic has confused me as I do not understand it.


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## OVT (Nov 29, 2011)

The key is the difference in gH between pre- and post- treated water. To calculate the amount of sodium / potassium added by the water softener based on the gH drop: How Much Sodium Does a Water Softener Put into Your Water? ?[censored]Pure Water Products, LLC .

In my case, a 4 degree drop (from 8 to 4 gH) was adding too much P and we turned the softener off via a by-pass valve.

Another consideration is that the efficiency degrades over time due to the removable and coated resin satturation. The removable resin can be replaced yearly (~$80). Re-coating the tank is a much more expensive proposition. If your system is rated at 4,000 gl per cycle new (before back flash), you need to re-coat when the system degrades to 2,000 gl per cycle. The side affect is that the amount of salt / potassium added to the tank decreases and the residual Ca and Mg increases over time.


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## MikeD73 (Feb 19, 2020)

Quizcat said:


> I have been reading some conflicting information that whole house mechanical water softeners that use an internal salt bath mechanism to soften water isn't good for aquariums. Yet, I also regularly read in the forums where many fish keepers add some aquarium salt to their freshwater tanks to condition their water, and many defend that practice pretty strongly from many years of having done so.
> 
> It would seem to me that the very minute residue of salt, the most of which is pumped down the drain after use within the water softener, would be a significantly less amount of salt than would be added to a tank by those that subscribe to the idea that adding salt to their aquariums is actually quite good for water conditioning.
> 
> ...





Exactly what OVT said...I've done this before.


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