Increasing Salinity via Water Change

[BMMMW]

Hi All,

First things first, this is a FOWLR tank. My salinity dropped over time from 1.025 to 1.021.

This is a 2 part question. First is if I want to increase the salinity from 1.021 to 1.025, is it safe to do via a water change?

Secondly, if I have a 125 gallon tank and a 30 gallon sump, when doing a water change of 30 gallons, what should the salinity of the 30 gallons be to achieve the 1.025?

Thanks!

 

[Duke4Life]

Hi All,

First things first, this is a FOWLR tank. My salinity dropped over time from 1.025 to 1.021.

This is a 2 part question. First is if I want to increase the salinity from 1.021 to 1.025, is it safe to do via a water change?

Secondly, if I have a 125 gallon tank and a 30 gallon sump, when doing a water change of 30 gallons, what should the salinity of the 30 gallons be to achieve the 1.025?

Thanks!

If your sump 95-100% full of water? How much live rock and sand?

 

[jsker]

Yes
Bump it up slowly so mix your water changes at a .27 and monitor the salinity

 

[Sabellafella]

Id assume for it to be somewere around 1.040 as im not good with math at the very moment but with fowlr jumping up insteadof down withyour sg should be taken slowly , i would try to do 3 seperate water changes throughtthe corse of a week , should do the trick

 

[BMMMW]

30 gallons in the actual sump. It can hold around 35-40.

Sand has been depleted over time from water changes and this is what I did not realize. Silly mistake if that's why the salinity dropped.

Sand-About 110 #'s and 120 #'s of rock.

Thanks Duke!

 

[BMMMW]

Id assume for it to be somewere around 1.040 as im not good with math at the very moment but with fowlr jumping up insteadof down withyour sg should be taken slowly , i would try to do 3 seperate water changes throughtthe corse of a week , should do the trick

Any way to do it all at once or is this too stressful for the fish?

 

[Sabellafella]

Any way to do it all at once or is this too stressful for the fish?

Personally when i acclimate my fish from qt witch is either at 1.015 or 1.020 will take about 3 hours and even then its stressful, your best bet is to do 20 gallons each time through a week at 1.030 and see where your at( edit also any saltmix passed 1.030 while mixing usually results in being cloudy and precipitation)

 

[Sabellafella]

I wouldnt seen why not sence its really not thatt big of a jump, but if you do water changes say once a month, i would pump it up to 1.023 and the next month back to your desired range

 

[Duke4Life]

Personally when i acclimate my fish from qt witch is either at 1.015 or 1.020 will take about 3 hours and even then its stressful, your best bet is to do 20 gallons each time through a week at 1.030 and see where your at

Agree with this, I was at 1.029 though hahaha

 

[BMMMW]

I wouldnt seen why not sence its really not thatt big of a jump, but if you do water changes say once a month, i would pump it up to 1.023 and the next month back to your desired range

Perfect, thanks. SO if I change 20 gallons, what salinity should that be to move it up? if 1.021 now, should the 20 gallons be 1.025 to achieve 1.023?

 

[Sabellafella]

No i think around 1.030 at 30gallons i wouldnt go higher then that

 

[Sabellafella]

Perfect, thanks. SO if I change 20 gallons, what salinity should that be to move it up? if 1.021 now, should the 20 gallons be 1.025 to achieve 1.023?

Basically if your tank is lets say 100 gallons at 1.021, if you did a 50% water change with your new mix at 1.025, your tank will br 1.023.. Thats basically the way i do math lol

 

[redfishbluefish]

The accepted rule is that you don't want to raise salinity more than 0.003 sg per day. However, I'm a firm believer in going slow. What I'd do is simply put saltwater in you ATO and let it rise slowly over the next couple days while you get evaporation.

If you do wish to do the "rip up" the salinity method, here are your calculations....you first need to estimate what you think you have in the way of water....this example will assume 130 gallons.
1.025 sg = 33.2 ppt
1.021 sg = 27.9 ppt

So I take out 30 gallons to do a water change and have 100 gallons at 1.021....and need to put 30 gallons back in at an unknown salinity to finally get 130 total gallons at 1.025 sg.
(1.021 x 100) + (Y x 30) = (1.025 x 130)
102.1 + 30Y = 133.25
30Y = 31.15
Y = 1.038 sg

You could also do this with ppt
(27.9 x 100) + (Y x 30) = (33.2 x 130)
2790 + 30Y = 4316
30Y = 1526
Y = 50.89 ppt
50.89 ppt = 1.038 sg

Now after doing these calculations, I'm pretty sure you will get calcium carbonate precipitation at this high a concentration...so it won't work.

 

[BMMMW]

Thanks for the replies. Sabellafella thanks for all the replies, I was on the same page at the end.

Redfishbluefish. I got the math after reading it a few times. Thanks!

I will go with raising the salinity by the ATO, I did not think of that and that seems the most fish friendly, which is my main goal.

Thanks again guys.

Cheers!

 

[Randy Holmes-Farley Verified Community Expert]

Late to the game, but I just want to agree that topping off with salt water is nearly always the best way to raise salinity.

I would say that I have sometimes added dry salt directly to one of my early sump chambers where there's a ton of mixing to easily dissolve salt fully before it gets to the display tank. Since I have limewater in my ATO, topping off with salt water would be a pain and would stop my calcium and alkalinity dosing.

 

[BMMMW]

More awesome info to know for my next tank. Thanks!

So why the Limewater?

 

[Randy Holmes-Farley Verified Community Expert]

More awesome info to know for my next tank. Thanks!

So why the Limewater?

It is the sole source of calcium and alkalinity for my tank. I think it is a good way to supplement most any tank, but by itself is not enough for many SPS tanks as it is limited by the rate of evaporation.

 

[BMMMW]

Cool!