does salinity swing ever so slightly throughout the day? I generally test my salinity early to mid afternoon and it always tests at 1.027. No matter how much freshwater I add I can't get it to drop. As well I just did a water change yesterday the salt I mixed I had at 1.021 trying to put a dent into it but it still stays stable at 1.027. I know it's not my refractometer because I was testing my salt as I was mixing it and it was and is still working perfectly fine.
Salinity swing help
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redfishbluefish
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You are using fresh water (RO/DI) for topoff, and not saltwater?
Salty1962
Wrasse and SPS Lover
Ditto on re-calibrating your refractor and installing an ATO will help you keep your salinity stable. You said you did a water change at 1.021 but what percentage of your tank capacity did you change. Adding salt water back into your tank at lower percentages won't change the total salinity by much in my experience.
@Zane @redfishbluefish @tdo @Salty1962 The tank is a 55gallon long and the refractometer is calibrated correctly and when I calibrated it the first time I tested it against my lfs to ensure I did it correctly. And no I don't top off with salt water I did a minuscule 5 gallon change but I should have seen some form of a drop. I'm planning on siphoning out another 5 and topping it off with freshwater and testing as I go to see if it lowers at all.
Do you have fish and coral?
Taking out 5 gallons and dumping in 5 gallons of rodi may not be the best way to approach this
Yeh it's a fully stocked tank I've had it running for over a year. And that's what I've been doing but I've been doing about 5 gallon pulls so if that won't make a difference then I'll have to do a larger one.
twilliard
Tank pests..
@Randy Holmes-Farley
Will be better to explain how to approach this.
Will be better to explain how to approach this.
Oceansize
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Leaving everything alone, I doubt you would be able to detect a rise in salinity in less than a day regardless of evaporation rate. Back before I had my ATO, it would take about 3 gallons in a roughly 70 gallon volume to lower my salinity by 0.001 (1.026 to 1.025)
Adding 5 gallons of SW at 1.021 to a 55 gallon at 1.027 would probably not make a noticeable difference. Adding 5 gallons at 0.00 to a 55 gallon at 1.027, yeah I would think that would drop the needle anywhere from 0.01 to 0.02.
Adding 5 gallons of SW at 1.021 to a 55 gallon at 1.027 would probably not make a noticeable difference. Adding 5 gallons at 0.00 to a 55 gallon at 1.027, yeah I would think that would drop the needle anywhere from 0.01 to 0.02.
@twilliard @Oceansize
You think it would be alright to just leave it as it is? I know it doesn't give me any play if my salinity spikes up. But everything seems happy. Is 1.27 bad enough to need to make a change?
You think it would be alright to just leave it as it is? I know it doesn't give me any play if my salinity spikes up. But everything seems happy. Is 1.27 bad enough to need to make a change?
redfishbluefish
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If I make the assumption that there is 50 gallons of water (at 1.027 sg) and you do a five gallon water change with 1.021 sg water, it calculates out to exactly 1.026 sg. I don't know why you are not seeing that drop. Now if you have a sump with additional water volume, the above calculations are bogus..
Randy Holmes-Farley
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FWIW, a sg of 1.027 is just fine. A large number of natural coral reefs have salinity that high or higher, and corals in the Red Sea thrive at much higher salinity.
If the specific gravity of the aquarium is at 1.0260 and you evaporate 2% (a typical daily evaporation amount), the specific gravity will rise to 1.0265.
When you really need to drop salinity, replacing some tank water with RO/DI will be a lot easier than doing a water change.
If you are at 1.027, replacing 2.2% of the water with fresh water will bring you to 35 ppt (1.2064) and replacing 5% will bring you to 1.0257.
If the specific gravity of the aquarium is at 1.0260 and you evaporate 2% (a typical daily evaporation amount), the specific gravity will rise to 1.0265.
When you really need to drop salinity, replacing some tank water with RO/DI will be a lot easier than doing a water change.
If you are at 1.027, replacing 2.2% of the water with fresh water will bring you to 35 ppt (1.2064) and replacing 5% will bring you to 1.0257.
redfishbluefish
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So if we assume a total of 70 gallons with a 5 gallon water change:
((35.8 x 65)+(27.9 x 5))/70 = 35.24
And 35.24ppm converts to 1.027 sg
((35.8 x 65)+(27.9 x 5))/70 = 35.24
And 35.24ppm converts to 1.027 sg
Salty1962
Wrasse and SPS Lover
I didn't mean your topoff, just your water change.
