# Quick Salinity Question



## BettaFriend (Oct 14, 2010)

Hey guys.

I know that I have had a saltwater tank since January, but I have a quick salinity question.

I was mixing 4 gallons saltwater in a 5g bucket. For some unknown reason I accidently put in 3 cups of InstantOcean instead of 2 1/2 (I was about to put in 4). I realized my mistake and was going to correct it after it all mixed.

I put in my airstone like I always do, and let it sit for afew hours (more than 6, but I can't remember). After I came back I tested the salinity and it came out 1.028. My tank is set to 1.024. I added a gallon of freshwater and tested it before I mixed it again and it came out at 1.022. Close, but this is a 30g tank and I don't want to change the salinity with relatively so much water.

What do I do for putting straight freshwater into already mixed for a day saltwater? I have it on airstone, but is it too late? Will it still mix? This is the first time I have run into this issue.

Please help if you can. Sorry it went long.


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## BettaFriend (Oct 14, 2010)

*I can't believe it!!!!!!*

What happened!?!?

I did not add the water that I mentioned in the earlier post. I went to check my salinity and I COULD NOT BELIEVE MY EYES!! It tested *1.031!!!!!*

What do I do about that?? How did it get so high!? I always test my water before adding the salt, and I always check the mix! The overflow was stopped afew days ago, and there is a layer of...protein(?) on the top of the water surface.

I really need to know what to do about this major problem! I don't see how those fish are still alive.

I have afew suspicions as to why it got so high, but I have something to do in afew minutes and I haven't eaten lunch.

Please help if you can! I don't want to kill them with a major salinity fluctuation, but I also don't want to kill them with the levels over the roof.

PLEASE HELP!!

Thanks!


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## cossie (Dec 19, 2010)

To lower the salinity simply carry out a small water change using Reverse osmosis water. Remember to leave the water for several hours before testing the salinity with a refractometer or hydrometer.

Hope this helps m8


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## BettaFriend (Oct 14, 2010)

I did leave this water out afew hours before testing it...actually, afew months! I meant to say that the water that showed *1.031* wasn't the new water, it was the water *in my 30g saltwater tank*! I am wondering how I am going to lower the salinity before killing the fish from it being too high, or killing them with the fluctuation.

Thanks for replying so quickly, cossie!;-)

Gotta go. I'll be back home in about 5 hours.


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## cossie (Dec 19, 2010)

lol just do a water change with RO water and then try again


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## BettaFriend (Oct 14, 2010)

Ok, but how big of a water change? It would be pretty easy to fluctuate the salinity to a lethal speed, right?


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## cossie (Dec 19, 2010)

5-10% water change and yes it can be easy


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## funlad3 (Oct 9, 2010)

Do a small (5%) dailly RO water change until the level slowly drops. The fish and corals can happily live at a slightly high or slightly low salinity. (That's what your 1.031 is...) They can't take massive fluctuations in the salinity level. Play it cool and your tank will be fine.

See why you want at least a 60 gallon?


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## cossie (Dec 19, 2010)

See why you want at least a 60 gallon? [/QUOTE]

tut, tut lol hes being sarcastic


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## funlad3 (Oct 9, 2010)

It's true though! A larger setup is more stable! IE the* OCEAN*!!!


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## cossie (Dec 19, 2010)

lol image a 1000g setup, about 150k for one of them lol


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## BettaFriend (Oct 14, 2010)

Is RO and Distilled water basically the same thing?

LOL, this is why I am glad I _don't_ have a 60g tank. There are other reasons I wish I do, though lol.

I have a 5g bucket of 1.0225 water (it was half way between 1.022 and 1.023). Can I add that at once to get my sump working? The water surface is getting a little bit scummy, and I am worried about the water just sitting in the sump. I mean, 5 gallons water that already has salt would be about the same as 1g of water wo/ salt (salinity 0), right?

Anyway, thanks guys for the help! Sorry for the emergency PM.


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## funlad3 (Oct 9, 2010)

If you add normal salt water to higher salt water, the normal SW only adds to the amount of salt. RODI (reverse osmosis de-ionized) water with a salinity of 0 "absorbs" much of the extra salinity. If that makes sense...


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## BettaFriend (Oct 14, 2010)

funlad3 said:


> If you add normal salt water to higher salt water, the normal SW only adds to the amount of salt.


LOL, in theory, maybe. Adding saltwater to more saltwater doesn't sound very promising, but I need to add at least 5g of water and I don't want a fluctuation in salinity. Also, even though I am adding saltwater to saltwater, the 1.0225 water would slightly dillute the 1.031, not make it worse. Even though it is adding saltwater, in relativity, it is adding more water, therefore lowering the salinity to somewhere in the middle.



funlad3 said:


> RODI (reverse osmosis de-ionized) water with a salinity of 0 "absorbs" much of the extra salinity. If that makes sense...


So distilled isn't the same thing? I don't know if my walmart has RO water, are there other names for RO water? I thought that they were pretty much the same thing as distilled.


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## funlad3 (Oct 9, 2010)

They both work just as well, but they ARE different. Adding five gallons of normal SW to your SW at 1.031 will only bring it down to maybe 1.029... I guess that that's okay! Be careful though!


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## kay-bee (Dec 6, 2006)

Distilled water and RO water are different.

In general terms, distilled water is water that has been converted to steam and then condensed back to water (thus removing all or most of the dissolved solids). RO water is water which has much of the total dissolved solids removed via reverse osmosis. 

The end product, however should be similar with an exception: I've read that if the cooling tubes used during the distilling process are copper the end product could have copper in it (which is harmful to inverts and corals) but I'm not sure if copper cooling tubes are still in use these days.


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## kay-bee (Dec 6, 2006)

I'd also recommend getting your salinity checked against a refractometer at a LFS.

Also 1.031 SG is elevated but not alarming (as long as the elevation gradually occurred). Specific gravity readings of the Red Sea has indicated the water there is 1.030 SG. 

You mentioned you have an airstone but how is your saltwater mixed?


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## BettaFriend (Oct 14, 2010)

Ouch! Seriously down to 1.029? I would have guessed in relativity that the 1.031 would not have been effected that much by the relatively small amount of 1.0225 water added. I wouldn't think that it would have such an effect. I would have thought that the completely RO/Distilled water would have made more of a difference (and if it makes more of a difference than 1.029, than I am in trouble!). I am relatively new to saltwater, though.

I guess I will try the 5 gallons of 1.0225 and test it afterwards. I'll post back later, but feel free to post before then!

Thanks for all y'all's help!


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## BettaFriend (Oct 14, 2010)

*It worked!*

I have to go soon, but a brief update.

You were right funlad3 (as usual)! After I added the 5 gallons of saltwater, my salinity measured 1.0295!

Update later! Thanks funlad3 and cossie!!


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## funlad3 (Oct 9, 2010)

And Kay-Bee! Not that I'm complaining that I actually got credit for something that I said on one of your threads! (For once... :fun 

Finding the new salinity is a simple ratio/fraction. Will I type it? Not here. Not now. I'm overloaded to the brim with homework. In fact, a paper I'm writing just finished printing! Yay... ;-)


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## BettaFriend (Oct 14, 2010)

kay-bee said:


> Distilled water and RO water are different.
> 
> In general terms, distilled water is water that has been converted to steam and then condensed back to water (thus removing all or most of the dissolved solids). RO water is water which has much of the total dissolved solids removed via reverse osmosis.
> 
> The end product, however should be similar with an exception: I've read that if the cooling tubes used during the distilling process are copper the end product could have copper in it (which is harmful to inverts and corals) but I'm not sure if copper cooling tubes are still in use these days.





kay-bee said:


> I'd also recommend getting your salinity checked against a refractometer at a LFS.
> 
> Also 1.031 SG is elevated but not alarming (as long as the elevation gradually occurred). Specific gravity readings of the Red Sea has indicated the water there is 1.030 SG.
> 
> You mentioned you have an airstone but how is your saltwater mixed?


So sorry kay-bee! I didn't know that there was a 2nd page yet so I didn't see either of these posts! Very sorry, I wasn't ignoring you.

Thanks for shedding some light on the difference between RO and distilled. I am glad to know, because people all over the forum are constantly wondering. 

Is there a copper test kit I can get? I don't really have any live coral (unless you consider whatever those orange things that don't appear to photosynthesize a coral), but I do have afew inverts.

As far as mixing the water, that is my main suspicion for the unknown salinity rise. Awhile back, before I knew that saltwater wasn't ready instantly, I just added the salt and poored in the water. That includes the almost pure salt at the bottom of the bucket. I noticed that it covered some of my LR, but the readings didn't say it was high (because I didn't mix it almost at all).

Now I have the saltwater in a 5g bucket. Usually I have 4 gallons at one time. I let it sit with an airstone (1 4" airstone attached to a small airstone "bit" thingy) and a 20-60g air pump as the source. The airstone is fairly near the bottom of the mixing bucket. I leave it for _at least_ 12 hours, but usually alot longer. At the end, all the clumps are completely dissolved. That is how I mix it. Is that Ok for mixing saltwater?

Thanks for the posts!


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## funlad3 (Oct 9, 2010)

That all sounds good!


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## TheOldSalt (Jan 28, 2005)

You have to leave newly mixed saltwater churning for a long time before you'll know it's true density, because the undissolved salt, much of which is extremely difficult to see, will continue to melt, and when it does, the salinity will rise.


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## BettaFriend (Oct 14, 2010)

TheOldSalt said:


> You have to leave newly mixed saltwater churning for a long time before you'll know it's true density, because the undissolved salt, much of which is extremely difficult to see, will continue to melt, and when it does, the salinity will rise.


I think that is what happend. Alot of un-dissolved salt slowly dissolving. What kind of churn do you guys use to mix the saltwater? Even with the airstone I still have alot of undissolved salt at the bottom of the bucket (that I don't put into the water).


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## funlad3 (Oct 9, 2010)

I always out a damaged Rio 2500 in a five gallon bucket. It works well enough!


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## kay-bee (Dec 6, 2006)

I currently use an eco-mod'd maxijet 1200 powerhead (~2000gph) in 18gal and 20gal rubbermaid type containers. and let that churn overnight at a minimum, but preferably for a few days before use to throughly dissolve the salt (though any type of circulation pump or powerhead will do). 

I also run the powerhead as I'm doing the water change.

The airstone method probably isn't doing the job correctly.

There are several companies which make copper test kits.


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## baileysup (Nov 25, 2009)

BettaFriend said:


> So distilled isn't the same thing? I don't know if my walmart has RO water, are there other names for RO water?


Walmart does have RO water, but they label it as "Drinking Water", and it should have a green cap on it. it says that it's "purified" which is the same thing as RO. i didn't think they had it at first either, so i just bought a name brand of purified water (which was only $1 a gal). when i went back, i read the label on their "drinking water", and it is indeed "purified" or RO water ($0.88 per gal).


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## baileysup (Nov 25, 2009)

i found out on the forum that "purified" water can be RO or distilled, or basically any kind of water. i was at walmart tonight, and i checked the label on their "drinking water", and it's purified via the reverse osmosis method. this makes walmart brand "drinking water" RO water. if anyone cares


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## funlad3 (Oct 9, 2010)

Hurray!!!!


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## kay-bee (Dec 6, 2006)

It would be interesting to know what the total dissolved solids/TDS meter reading of that water is.


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## funlad3 (Oct 9, 2010)

Yet another good point!


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