Does Aquarium Salt makes water harder?

[fddlss]

I recently 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. They are African cichlids, so they are able to handle those salt levels well.

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

Thanks.

[mattrox]

Replacing the water due to evaporation will increase the hardness slowly, and can account for small differences. As water evaporates the hardness increases due to the smaller volume. When you add water, more minerals go in.... this evaporates and the hardness is higher than before. Top up again and more minerals go in again.... evaporates and hardness increases.

Salts for ICH are likely to be sodium salts not Calcium or Magnesium salts, therefore the hardness will not change.

It is likely that the increase from 7.5 to 8 is due to the limestone/crushed coral. Sounds like it is time for a 30% pwc though. Test the hardness 1 day after a pwc.

[fddlss]

Thanks! I was thinking about doing a series of PWCs to reduce salinity since I'm done with the ich treatment. I've started to drop the temperature back to normal, slowly, and I will do a large water change today and another one tomorrow. I'm not sure if I should do 3 or 4 smaller water changes over the course of 4 days or if I should do 2 50%-60% water changes to reduce salinity. What I don't want to do is, drop the hardness and salinity to drastically by doing large water changes that's why I thought about doing more, but smaller water changes; However, the other question is if 3 or 4 30% water changes will remove salinity in full.

By the way, my tap water's pH is 7.5 and my fear is that by doing large water changes the CC/limestone will not be able to adjust the hardness quick enough and it might affect the fish. By doing 20%-30% water changes the drop in pH will not be as big and it will take less time for the CC/limestone to adjust it.

On the other hand, if it's the CC/limestone that are making the water harder that's great news because I have African cichlids, but like you said, the only way to be sure of that it's to do a large water change, wait a day or two and test the hardness. Also, water is not evaporating so fast now that I'm dropping the temperature.

[fddlss]

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%.

[mattrox]

Test the pH your tap water straight out of the tap, then leave some sitting in a cup overnight and test again. Off-gassing of CO2 causes an increase in pH too. This is important to know.

[fddlss]

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.

In the meantime, I really don't know what to think or guess. Any clues?


Thanks for your help!

[FoxRob]

Are you using test strips?

[fddlss]

Hey! I just thought about something... (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 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...

[fddlss]

I'm using the API test kit