What is the lowest salinity you've had in your reef tank?

[Daved4]

Hey everyone. I'm curious to see what anyone has to say about the lowest they've seen their salinity in their tank with corals still thriving? I recently realized my tank was running at 1.020 for quite a long period of time. Verified by 2 separate digital Milwaukee checkers. I've since brought it back up to 1.026 and have seen a huge improvement but things were actually living and growing at 1.020 including sps.

 

[ryanjohn1]

Hey everyone. I'm curious to see what anyone has to say about the lowest they've seen their salinity in their tank with corals still thriving? I recently realized my tank was running at 1.020 for quite a long period of time. Verified by 2 separate digital Milwaukee checkers. I've since brought it back up to 1.026 and have seen a huge improvement but things were actually living and growing at 1.020 including sps.

Been dealing with that sorta situation myself. However I believe it’s been the Red Sea coral pro salt mix.

 

[Daved4]

Been dealing with that sorta situation myself. However I believe it’s been the Red Sea coral pro salt mix.

I started selling a lot more coral last year and from June to December bagged about 100 pieces. And never topped off with salt. It was such a slow drop that it seemed like everything just adjusted and adapted. I was truly shocked when I realized what happened

 

[ryanjohn1]

I started selling a lot more coral last year and from June to December bagged about 100 pieces. And never topped off with salt. It was such a slow drop that it seemed like everything just adjusted and adapted. I was truly shocked when I realized what happened

I’ve got Sps and lps and they all look pretty nice. Been mixing water properly for years. And it seems my last bucket of coral pro holds proper salinity for like five minutes then drops. Tank was at 1.022 -1.021. Put 1.025 in ato to slowly bring up. Had to do this 2 or 3 weeks ago as well

 

[vetteguy53081]

Hey everyone. I'm curious to see what anyone has to say about the lowest they've seen their salinity in their tank with corals still thriving? I recently realized my tank was running at 1.020 for quite a long period of time. Verified by 2 separate digital Milwaukee checkers. I've since brought it back up to 1.026 and have seen a huge improvement but things were actually living and growing at 1.020 including sps.

1.023 due to false readings why its important to calibrate checkers. I now check salinity every 3 days

 

[ilikefish69]

I used RO water to calibrate a refractometer when setting up my tank last March, and after getting a hunch from testing LFS water who keeps stuff at 1.020, my refractometer was reading 1.026. So basically same boat as you. It was beginning of December when I bought the Hanna salinity meter, and what I’ve noticed is mostly faster growth from my soft corals. Of course is completely anecdotal because my tank also was coming into its “established” environment , so I can’t really link the two with other variables.

the scrambled eggs zoa frag had 3 on it, purchased in May 2022, and opened every day but didn’t spit new polyps until February of this year. 3 polyps for over 6 months at 1.020. It has since taken off , as well as a ricordea mushroom that’s gonna bonkers and a Kenya tree and Yuma have all exploded recently.

if you are super curious all of those pieces have their “recently introduced” pictures in my build thread

 

[o2manyfish]

With very slow changes to salinity you wont see horrible results. It's when there is rapid drop off that you will see a problem. Returning salinity to normal quickly doesn't seem to make things worse (after a rapid salinity drop).

Dave B

 

[TnFishwater98]

I found this interesting, not sure how it fully relates to saltwater tanks. But still good knowledge.

Ocean salinity

There are many chemicals in seawater that make it salty. Most of them get there from rivers carrying chemicals dissolved out of rock and soil. The main one is sodium chloride, often just called salt. Most seawater has about 35 g (7 teaspoons) of salt in every 1,000 g (about a litre) of water...

www.sciencelearn.org.nz

 

[TnFishwater98]

And another ‘kid’ friendly article. I personally don’t think our seas are in danger of dying because we Know temps will inevitably rise.. (Opinion)

A Salty Coral Secret: How High Salinity Helps Corals To Be Stronger

Corals are mysterious animals that have been around for ages. They are the creators of beautiful reefs. Sadly, the reefs that we love to look at are in danger of overheating and are disappearing from our planet. While this sounds bad, not all corals are affected the same way by warm seawater...

kids.frontiersin.org

 

[CodyBot]

1.023 due to false readings why its important to calibrate checkers. I now check salinity every 3 days

I would recommend testing the water of the national vendors that you buy corals from. You'll find that it's not uncommon to get gorgeous corals in bags of saltwater that are roughly 1.023. The stability of the salinity is more important than the number, same as most parameters, within reason.

 

[Randy Holmes-Farley]

And it seems my last bucket of coral pro holds proper salinity for like five minutes then drops.

I have no idea what that could be, other than you had not mixed it well before measurement or its a temperature effect on your measuring device that was not accounting for it. Salinity doesn't change once all salt is dissolved.

The only thing high alk mixes do over time is precipitate calcium carbonate, and the impact of that effect on salinity is not very large.

 

[ryanjohn1]

I have no idea what that could be, other than you had not mixed it well before measurement or its a temperature effect on your measuring device that was not accounting for it. Salinity doesn't change once all salt is dissolved.

The only thing high alk mixes do over time is precipitate calcium carbonate, and the impact of that effect on salinity is not very large.

I believe it was the pump heating up the water and causing fluctuations in readings. Refractometer and Hanna salinity

 

[Randy Holmes-Farley]

I believe it was the pump heating up the water and causing fluctuations in readings. Refractometer and Hanna salinity

Ok, so that makes it a false reading, not an actual salinity change.

 

[Mperry622]

I am in a odd situation. my apex is reporting my salinity was getting to 29.8 PPT,(cleaned probe and calibrated) then tested with refractometer and hydrometer, both were spot on @ 35ppt (dead on) my Hanna wasn't calibrated, stopped at LFS grabbed a calibration pouch and it is reading 100% identical to my apex...Now I am not sure what to do. I stopped my ato for the last two days and replaced with seawater... but i am not sure if it is indeed high or low... any input?

hydrometer = 35
refractometer = 34-35
apex 29.8
Hanna 30.1

who the heck do I believe?

apex and Hanna were both calibrated together..

I am stopping to get some Morton table salt to make up three batches of Randy's calibration liquid for each. I made one and didn't realize one does not calibrate all three types of devices. :-(

 

[Daved4]

I am in a odd situation. my apex is reporting my salinity was getting to 29.8 PPT,(cleaned probe and calibrated) then tested with refractometer and hydrometer, both were spot on @ 35ppt (dead on) my Hanna wasn't calibrated, stopped at LFS grabbed a calibration pouch and it is reading 100% identical to my apex...Now I am not sure what to do. I stopped my ato for the last two days and replaced with seawater... but i am not sure if it is indeed high or low... any input?

hydrometer = 35
refractometer = 34-35
apex 29.8
Hanna 30.1

who the heck do I believe?

apex and Hanna were both calibrated together..

I am stopping to get some Morton table salt to make up three batches of Randy's calibration liquid for each. I made one and didn't realize one does not calibrate all three types of devices. :-(

Honestly I would try to get it tested with a digital tester like.milwaukee. I wouldn't trust the apex and if i had to trust any of those I would personally use the refractometer and calibrate to 0 with rodi

 

[dirty_south87]

Been dealing with that sorta situation myself. However I believe it’s been the Red Sea coral pro salt mix.

I agree with that. Been seeing that since I started this bucket I’m on

 

[ilikefish69]

Honestly I would try to get it tested with a digital tester like.milwaukee. I wouldn't trust the apex and if i had to trust any of those I would personally use the refractometer and calibrate to 0 with rodi

Calibrating a refractometer with RODI is a last resort, most consider it a “no-no” and I sure learned my lesson in it awhile back.

my Hanna salinity tester has always been accurate, I calibrate it every couple of weeks. It has never been off. I do wish it would go into the thousandths, but it is accurate.

no experience with apex, I would just end up breaking it and giving it away after a week.

hydrometers are the most accurate. I believe you need to temperature adjust the reading in some of them. Could be where you are getting the wonky results

 

[Mperry622]

Calibrating a refractometer with RODI is a last resort, most consider it a “no-no” and I sure learned my lesson in it awhile back.

my Hanna salinity tester has always been accurate, I calibrate it every couple of weeks. It has never been off. I do wish it would go into the thousandths, but it is accurate.

no experience with apex, I would just end up breaking it and giving it away after a week.

hydrometers are the most accurate. I believe you need to temperature adjust the reading in some of them. Could be where you are getting the wonky results

I have never trusted my Apex probe I simply use it as a guide. It's never really been that far off and I noticed it started declining. Testing with the refractometer and the hydrometer give the same results but the Hana and the Apex also share the same results I just don't know which one to believe.. my wife just looks at me and shakes her head when I try to explain the four readings....

I have a seeking suspicion I wasn't keeping up with replacing the amount my skimmer was pulling out

 

[ryanjohn1]

I agree with that. Been seeing that since I started this bucket I’m on

Apparently they changed the mix!

 

[dirty_south87]

Apparently they changed the mix!

Where did you find that at? I’ve been searching for some info since they would not email me the batch information