Would this happening kill SPS?

Animal Chin · Sep 26, 2018

Ugh, sometimes being a human really messes up the whole keeping a reef tank thing. So, my best guess is I made up RODI water and FORGOT to add the salt before doing a water change on my 125 gallon and I removed 15 gallons of salt water and replaced it with 15 gallons of water that may not have contained salt...lol

So not knowing this I see one of my acro's STN over a coupld of days. I"m fragging it trying to keep peices but its too late. Lost the colony. I'm checking alk, phos, all the normal stuff but forget salinty. My tank has been stable in salinity for 4 years, why would I. Next day, another acro starts slowly bleaching. Takes about 4 days and its dead. I test my salinity and its fallen to 1.021 and I usually keep it at 1.025! CRAP!

I add some salt slowly over a few days, start getting it back up, yesterday my ausi poci starts bleaching! But by now Im back up to normal salinity but JUST got it there.

So question. Is the salinity the main culprit here? Is it known to kill off sps colonies if it drops suddenly?

RichtheReefer21 · Sep 26, 2018

ugh, losing coral that takes so long to grow sucks!

I would post this in "reef chemistry" and/or "SPS discussion"

Crabs McJones · Sep 26, 2018

Major salinity swings like that can cause what you're seeing. What about the rest of your parameters? Alk, calcium, mag? Did you add more of this as well? Taking out saltwater that contained those elements and adding in freshwater that didn't, could have dipped those numbers as well. Now that you have your salinity back up, just check the rest of your parameters, if everything is on id say leave everything be to recover.

Animal Chin · Sep 26, 2018

I dose Alk and cal so those stayed stable and I've slowly added salt over the last week to get it back up. If thats whats nuking my coral I get it, I messed up. I was more worried that this isn't something that would kill them and something else is wrong....

Crabs McJones · Sep 26, 2018

Animal Chin said:
I dose Alk and cal so those stayed stable and I've slowly added salt over the last week to get it back up. If thats whats nuking my coral I get it, I messed up. I was more worried that this isn't something that would kill them and something else is wrong....

Nope, unfortunately it sounds like that is what the issue is

But i'm glad you were able to get everything back on track.

Aquavaj · Sep 26, 2018

15g of fw is going to cause a bigger salinity swing than that. More than likely the new water was low in salinity but not straight rodi.

saltyfilmfolks · Sep 26, 2018

Yup. That’ll kill em.
Keep in mind , salinity is also density of minerals in the water.
When salinity changes, alk cal mag etc also change.
Ie , you are watering down a soloution.

Flippers4pups · Sep 26, 2018

Sorry to hear this. Hopefully it starts to improve soon.

Animal Chin · Sep 26, 2018

Aquavaj said:
15g of fw is going to cause a bigger salinity swing than that. More than likely the new water was low in salinity but not straight rodi.

Well I do use 3 5 gallon jugs so it could have been one of the jugs or perhaps 2 of them. I'm not sure to be honest, its just my guess that I missed adding salt. Regardless, my salinity was really low however it happened...

Flippers4pups · Sep 26, 2018

Animal Chin said:
Well I do use 3 5 gallon jugs so it could have been one of the jugs or perhaps 2 of them. I'm not sure to be honest, its just my guess that I missed adding salt. Regardless, my salinity was really low however it happened...

Do you have a ATO on this tank?

Animal Chin · Sep 26, 2018

I do. ATO, Controler for dosing, refugium...

Flippers4pups · Sep 26, 2018

Animal Chin said:
I do. ATO, Controler for dosing, refugium...

Okay, thanks! Very nice system you have!

Flippers4pups · Sep 26, 2018

@Animal Chin, you should do a build thread in the members tank forum here. We would love to see more of your tank!

Perry · Sep 26, 2018

Alk likely culprit, yes all main minerals and trace minerals would drop too, but usually less forging than salinity, or other minerals. A quick drop in alkalinity is no accepted by many sps. Hopefully a quick recovery soon, also agree, nice aquarium!

Justin Aretz · Jan 28, 2021

A salinity drop took out approx 30% of a major grow out system with over 150 colonies in it. Like mentioned, IF immediate dilution was the cause, check all elements, including trace (send ATI or triton icp). Also study whether or not your ATO is slowly diluting the tank water. Multiple ATOs have done this to my systems over periods of time, including gravity fed.

As a side note, how high above the waterline are your black boxes mounted?

Greg P · Jan 28, 2021

Justin Aretz said:
A salinity drop took out approx 30% of a major grow out system with over 150 colonies in it. Like mentioned, IF immediate dilution was the cause, check all elements, including trace (send ATI or triton icp). Also study whether or not your ATO is slowly diluting the tank water. Multiple ATOs have done this to my systems over periods of time, including gravity fed.

As a side note, how high above the waterline are your black boxes mounted?

28 month old thread @Justin Aretz ...