# Does Aquarium Salt makes water harder?



## fddlss (Apr 7, 2011)

As some of you know, I treated my fish for Ich using 2 tablespoons of aquarium salt for every 5 gallons over a period of 48 hours (4 doses every 12 hours). The tank is a 120 gallon. Now, I'm at the end of the treatment (10 days after adding the last dose of salt) and about 2 days ago, and yesterday, I tested my water and the pH went from 7.5 to 8.1, KH went from 4.5 to 6 dKH and GH went from 6 to 10 dKH, this is great (if it stays that way), but I don't know if this is due to the salt (API Freshwater Aquarium Salt) or to the crushed coral and limestone rocks that are finally working (after 1 month). Also, when I tested 2 or 3 days ago, pH was 8.0, KH 5.5, GH 9 and last night the readings were ph 8.1-8.2, KH 6 dKH, and GH 10 dKH. I haven't added any more salt or performed any water changes since the treatment started about 11 days ago. Also, I've been replacing about 1 gallon of water everyday in the sump because of evaporation, due to the water being 87.5 F degrees.

So, is the hardness due to the salt or just CC and limestone doing their job (after a month with no increase in hardness)?


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## BillD (May 17, 2005)

The salt will increase the TDS, Total Dissolved Solids, so will affect one of those readings. If the crushed coral and limestone and limestone are increasing the natural hardness of your water, every time you do a water change with softer water, you will have a change in the TDS. This is something I would prefer to avoid, so I wouldn't use any substrate or stone that altered the water chemistry, preferring to have a more stable condition, rather than an "ideal" condition.
Adding water daily will increase your overall hardness as the water evaporating leaves behind all the dissolved minerals. I suspect this and the salt have had more to do with the increase in hardness than your coral and limestone. Nest time you need salt for a treatment save your money and buy kosher or picking salt. It is probably significantly cheaper than what you used.


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## fddlss (Apr 7, 2011)

Thanks BillD.

I used the regular API aquarium salt, which is inexpensive.

I think I will notice if it was the salt or CC+limestone after I do a series of daily partial water changes to remove salinity from the water and put an end to the Ich treatment. I will do about 3 or 4 40% water changes starting tomorrow, until Friday or Saturday, to remove salinity and I'm also gradually lowering the Temp. back to normal.

After I do all that, I will wait about a week and then test again and see what the hardness is. If it stayed the same, it's probably the CC+limestone doing their job, if it dropped it was the salt increasing hardness.

Does this make sense?


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## DJRansome (Oct 29, 2005)

You might want to do fewer water changes but remove a larger percentage of the water to really get the salt out.


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## DrTim's (Jun 8, 2010)

Salt - NaCl does nothing to your water hardness which is a measure of the multivalent cations in your water which is mostly Calcium (Ca++) and Magnesium (Mg++). Sodium (Na) is monovalent so does not contribute towards water hardness.


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## fddlss (Apr 7, 2011)

DJRansome said:


> You might want to do fewer water changes but remove a larger percentage of the water to really get the salt out.


Then, maybe 2 60% water changes should do it? One today and the other one tomorrow.


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## fddlss (Apr 7, 2011)

DrTim's said:


> Salt - NaCl does nothing to your water hardness which is a measure of the multivalent cations in your water which is mostly Calcium (Ca++) and Magnesium (Mg++). Sodium (Na) is monovalent so does not contribute towards water hardness.


If that's the case, then maybe my limestone and crushed coral are working, which would be great! Thanks.


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## DrTim's (Jun 8, 2010)

yes I think they are


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## fddlss (Apr 7, 2011)

Thanks. I did a 50% water change last night, will perform another 50% WC tonight, and probably a 20% WC tomorrow to remove salinity and then wait about 2 days and test the hardness. That should indicate me if CC+Limestone are working, which I think they finally are.


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## fddlss (Apr 7, 2011)

I tested for hardness today, 24 hours after doing the 50% PWC and pH dropped to 7.5 and KH to 4 dKH. I'm doing another 50% water change right now to remove salinity, do you think two 50% PWC are enough to remove the salt or should I do another 20-30% PWC tomorrow, too? I will wait about 4 days and see if the hardness raises again, which it should, that would confirm that the CC/limestone are working. My tap water has a pH of 7.5 that's probably why ph in my tank dropped after doing a big PWC, and 24 hours wasn't enough for CC/limestone to raise it again.


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## prov356 (Sep 20, 2006)

> My tap water has a pH of 7.5 that's probably why ph in my tank dropped after doing a big PWC, and 24 hours wasn't enough for CC/limestone to raise it again.


That's typically what happens. It works, but not fast enough to replenish if you're on a regular water change schedule.


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## fddlss (Apr 7, 2011)

Yup. It should be okay when doing 10-20% weekly water changes, but a 50% WC is too much for the CC/limestone to handle in 24 hours.

By the way it took about 2 weeks for Nitrates to climb from 5 PPM, to 30 PPM, which I think it's pretty good, isn't it? Probably because I have just a few fish (9 -small). Ammonia and Nitrite always 0 PPM. I'm using the API Master Test Kit, and I'm saying that Nitrates were at 30 PPM but I'm not sure, because it's so difficult to differentiate between the orange colors, but it was under 40 PPM for sure. Somewhere between 10 PPM and 35 PPM.

Also, do you think I need to do another PWC (maybe 20-30%) today to remove any salt left, or two 50% PWCs was enough?

As always,

Thank you.


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## BillD (May 17, 2005)

fddlss said:


> I tested for hardness today, 24 hours after doing the 50% PWC and pH dropped to 7.5 and KH to 4 dKH. I'm doing another 50% water change right now to remove salinity, do you think two 50% PWC are enough to remove the salt or should I do another 20-30% PWC tomorrow, too? I will wait about 4 days and see if the hardness raises again, which it should, that would confirm that the CC/limestone are working. My tap water has a pH of 7.5 that's probably why ph in my tank dropped after doing a big PWC, and 24 hours wasn't enough for CC/limestone to raise it again.


This is why I prefer to have inert substrate and allow the water parameters to stay more consistent. The problem as I see it is not pH, but in this case there was a large change in the TDS of the water, and this can lead to osmotic shock in extreme cases. I no longer concern myself with pH and haven't tested for it in years. I live with the water I have, and so do the fish, without any problems.


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## fddlss (Apr 7, 2011)

Hi BillD,

That makes sense, it's better to have a stable, but not ideal pH, than to have a changing pH. I will set up a QT tank so hopefully I will not have to add those amounts of salt to the main tank again and I will keep my weekly water changes at 20% or less every 7 days. The CC/Limestone should be able to handle that.


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## Number6 (Mar 13, 2003)

fddlss said:


> Hi BillD,
> 
> That makes sense, it's better to have a stable, but not ideal pH, than to have a changing pH.


That isn't what Billd was saying... Bill mentions TDS (Total disolved solids).


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## fddlss (Apr 7, 2011)

Number6 said:


> fddlss said:
> 
> 
> > Hi BillD,
> ...


I know, that's why I said that hopefully my TDS level will not change in the future because I will setup a QT tank.


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## fddlss (Apr 7, 2011)

I did a 50% PWC last week Wedsnesday, another 50% PWC the day after and a 25% water change last Saturday, that same Saturday (the 21st), before de PWC, the pH had dropped to my tap's pH, which is 7.5, due to the big 50% water changes; However, I tested for hardness today and it raised again, pH 8.0, KH 5.5 dKH, GH 8 dKH, it will probably keep raising until it reaches a pH of 8.2 or so.
With that said, we can conclude that the raise in hardness is due to the crushed coral and limestone, and a 15% water change every Saturday shouldn't be a big deal in terms of hardness, I don't think it will affect it as long as I keep it under 20%.


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## DJRansome (Oct 29, 2005)

I don't know what is causing your fluctuations, but they are harmful for the fish.


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## fddlss (Apr 7, 2011)

The fluctuations were caused by the big water changes to remove the TDS from the water and put an end to the Ich treatment. Now, those fluctuations will not happen because I will be changing no more than 15% or 20% of the water weekly and I will set up a QT tank.


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## fddlss (Apr 7, 2011)

Everything was looking good... until last night.

Here's a better explanation of how things went:

Just FYI, my tap's pH is 7.5 when left overnight and 8.2 or 8.6 (I don't remember exactly) straight out of the tap.

I'm a little worried because last night I tested again for hardness, to see if pH and KH were the same or if they had increased. Well, last night, 24 hours after the results I told you on my last post, my pH had dropped to 7.5, KH to 5 dKH, and GH to 7 dKH. The change in KH and GH wasn't much, especially when KH went from 5.5 to 5, which the .5 from Wednesday could of been a misjudgement in the colors on my part. But pH showed a big drop in 24 hours, from 8.0 to 7.5, then I tested again this morning (10 hours after) and pH had increased to 7.8 and KH was the same at 5 dKH. So, now I'm doubt, I don't know if on Wednesday, when pH was supposedly 8.0, I read the wrong color or what, because I don't have any driftwood or something that would make pH fluctuate, I didn't do any kind of water changes either. This are the results so you have a better idea of what's going on:

05/16: About to finish Ich treatment and checked hardness just out of curiosity. I treated Ich with salt+heat. I began dropping the temp. at this point and preparing for a water change later on the week. pH was 8.2, KH was 6 dKH and GH was 10 or 11 dKH.

05/18 (Night): 50% PWC to reduce salinity.

05/19 (Night): Tested hardness before doing another water change. pH 7.5, KH 4.5. Then, I performed another 50% PWC.

05/18: Did nothing

05/19 (Noon): Tested hardnes: pH 7.5, KH 4.5. Then, I did a 25% PWC.

05/20: Did nothing

05/21: Did nothing

05/22: Did nothing

05/23: Did nothing

05/24: Did nothing. Just added 1 gallon of dechlorinated tap water to my sump (evaporation). Sump is about 30 gallons and tank is 120, so I don't think that 1 gallon affects anything at all.

05/25: Tested for hardness: pH 8.0, KH 5.5 dKH, GH 8 dKH (or 7.5). This was 4 days after the last PWC.

05/26 (10:15 PM): Tested for hardness: pH 7.5, KH 5 dKH, GH 7 dKH

05/27 (7:45 AM): Tested for hardness: pH 7.8, KH 5 dKH

I know that the readings from 05/26 and 27 are correct because I doubled checked. The readings from 05/25 should be accurate because I always pay attention and make sure, but we all make mistakes, so maybe I read the wrong color on the chart or something (I checked it with day light and artificial light).

Either I got the wrong readings on 05/25 (which I'm 90% sure I didn't) or there's something going on that I'm unaware of.

Are there up and downs like that when CC/limestone are doing their job until it stabilizes?

Should I give it more time to stabilize from the big PWCs from last week?

I will check again tonight when I get home and continue checking to see if it goes up and down or it raises steadily until it stops and stays at a certain point.

Hey! I just thought about something, as I write this post... (sometimes I think. LOL). From Wed. night (05/25 after testing for hardness) until yesterday afternoon (05/26, 2 hours before testing for hardness) I left one (only one) of the glass lids closed (it's a 5ft. tank with two glass lids), and I never close the lids for temperature reasons, but this time I did to see if temp. would stay the same and it raised the temp. by 1.5 degrees or so. That's why last afternoon I opened that lid again, left it open, and about two hours later I tested for hardness.

Do you guys think that the drop in pH (but not such a big drop in KH and GH) could be because of that glass lid being closed? Maybe something to do with oxygen exchange or CO2?

I don't add CO2 to my tank and I have an air stone in the tank but I don't think the air stone does much.

Just a thought...

Thanks for your help!


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## prov356 (Sep 20, 2006)

> my pH had dropped to 7.5, KH to 5 dKH, and GH to 7 dKH.


You're just going to make yourself crazy with this. My suggestion would be to use the sodium bicarb and your KH and pH will be fine. Worrying about the changes you're seeing in pH and KH and trying to use substrate to stabilize or worrying about whether glass lids are open or closed, or did I read the color charts correctly, or how your tap pH changes after sitting, etc just isn't worth the hassle IMO. Get on a regular routine of using sodium bicarb and you probably won't need to test or worry about pH and KH again.


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## DJRansome (Oct 29, 2005)

prov356 said:


> You're just going to make yourself crazy with this. My suggestion would be to use the sodium bicarb and your KH and pH will be fine. Worrying about the changes you're seeing in pH and KH and trying to use substrate to stabilize or worrying about whether glass lids are open or closed, or did I read the color charts correctly, or how your tap pH changes after sitting, etc just isn't worth the hassle IMO. Get on a regular routine of using sodium bicarb and you probably won't need to test or worry about pH and KH again.


Amen.


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## fddlss (Apr 7, 2011)

I finally agree with you guys, I wanted to go the natural way without having to add anything or worry about not forgetting to add something, but I have no choice. At least I tried and had my own experience.

On 5/27 morning pH was 7.8, KH 5 dKH, as I posted above. Then, I tested again at night (5/27) without doing anything to the tank, but adding 1 gallon of water in the sump to refill it, KH was the same and pH was 8.0 (raised from 7.8 in the morning), so that was a good signal in favor of my hypothesis, that closing the lids drops pH. However, On 5/28 I didn't do anything to the tank, lids stayed open, just added 1 gallon of water to refill the sump, I tested for pH and it had dropped to 7.8, KH was the same. Today, 5/29, pH is still 7.8, why it dropped from 8.0 on Friday (05/27) night I don't know... Also, it's really difficult to differentiate the colors of 7.4 and 7.8 in the API chart because the liquid looks different when looking at it from different angles and light sources. That's why I bought a Pinpoint pH meter, that should arrive next week . Anyways, I will test again tonight and try the baking soda method starting next week and just stick to it.

Now I'm just curios to know why is my pH fluctuating, maybe I'm just getting the wrong readings or if not there's must something that's making it swing...

Thanks!


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## prov356 (Sep 20, 2006)

There are many reasons why pH can swing, but just use the baking soda and it won't swing and you won't need the pinpoint tester. The API kit does perfectly well at giving a ballpark pH reading, which is all you need. All the fish need is for it to be in a range. Striving for a precise pH reading just isn't necessary. I still think you're putting too much into this. There's nothing to be gained by it.


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## fddlss (Apr 7, 2011)

Thanks Tim. Obviously I need to find it how much baking soda I need and add it gradyally, so should I start by adding a few teaspoons to one gallon of aquarium water and do the math to know how much would I need for my whole tank to raise it from x to x, and then just find out how much will I need with each 20% water change?


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## prov356 (Sep 20, 2006)

Yes, test by adding a little and noting the change. Then you can work out how much to add periodically, typically at the water change.


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## Number6 (Mar 13, 2003)

Your replies to Prov make me worry you are still planning on checking pH on this tank... please! return the pH monitor and get your money back and STOP measuring pH... biggest waste of time and misinfo in this entire hobby!

+1 for Prov's advice... start adding and monitoring KH. :thumb:


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## fddlss (Apr 7, 2011)

Number6 said:


> Your replies to Prov make me worry you are still planning on checking pH on this tank... please! return the pH monitor and get your money back and STOP measuring pH... biggest waste of time and misinfo in this entire hobby!
> 
> +1 for Prov's advice... start adding and monitoring KH. :thumb:


Haha thanks! I know that if KH is hard pH shouldn't move therefore I should measure KH and forget about pH. My question above was how to get started and figure out how much baking soda I need to raise the KH.


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## fox (Jun 11, 2009)

fddlss said:


> >SNIP<
> My question above was how to get started and figure out how much baking soda I need to raise the KH.


You add a little ... suppose 1 tablespoon ... Wait an hour and test for change in ph/ kh. If it goes up too high a tablespoon was too much don't use so much next time :wink: ... if remains way too low a tablespoon was too little next time use a little bit more. If it goes to somwhere close to target then stop and you found you dosage. :thumb: Not really rocket science.

Once you establish your dosage and get into a habit of doing things the same at each maintenance you will no longer need to check these things ... I know I just buffer our tanks to what each one req's from past experience and some tanks have not been tested in :roll: :roll: a year or so :roll: :roll:


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## fddlss (Apr 7, 2011)

fox said:


> fddlss said:
> 
> 
> > >SNIP<
> ...


That's what I would do and finally put an end to this hardness deal.

Thank you!


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