Increase salinity - how quickly?

[Simon_M]

I read and understand that salt can't be directly added to my display tank to raise the salinity.

My solution has been to turn off the electrics and syphon off 20 litres (1/9th of tank) and mix in extra salt.

I wanted to raise it from 33 g / litre to 35 g / litre.

I calculated the amount of salt to mix for my tank and divided this by 35 and added this to the 20 litres of water. Mixed and heated in the usual way.

I have added half back to the tank and waited 30 minutes before adding the remainder. I plan to repeat this tomorrow.

33 g/ litre to 33.5g / delay / 34 g and tomorrow "rinse and repeat". Is that OK or is there a better way?

I don't want to wait too long with the electrics off e.g. no heating (probably not an issue) and no filtration running (more of an issue). With a reduced water level the filtration and heating can't be run, at least not until half the brine has been added.

The 175g of salt I added in dissolved easily and the new salinity was clearly off the scale because the brine mix is more concentrated.

The tank occupants are a clean up crew (3 hermits, 3 snails and a shrimp) and one Clown fish.

 

[dvgyfresh]

Why not just top off with salt water instead of RO

 

[uhgster1]

I just dealt with this recently, my daughter moved my ato sensor and my salinity dropped down to 1.019. Take some water out, actually good time for a water change, but add more water than usual. Check the level in a day or two and see where it sits. Just add regular (ie fresh correct parameter salt water) and let it get back to normal with evaporation. It took me two days to get back to normal. You don’t want to make a concentrated solution because it actually precipitates some elements and can actually burn some coral.

 

[Simon_M]

Tank is covered so evaporation is minimal - would have to wait a long time (weeks)?

 

[Simon_M]

Tank is "cycled" but don't have much algae and not reached the "ugly" stage - there is no coral - to burn. Evaporation seems to be almost non existent but one issue I had was my ATO turning on if I cycled the electrics. I now catch the additional water added in a jug and put it back in my RO/DI tank to prevent diluting the mix.

 

[Simon_M]

Since I had the electrics off and my plasterer's bucket holds 35 litres, I syphoned off some more water and let it mix - so the increase isn't too great.

What is a significant increase for my Clown e.g. will moving from 33 to 33.5 be an acceptable increase (later to 34) and tomorrow to 34.5 and then 35?

 

[uhgster1]

How bad was the salinity drop?

 

[Simon_M]

35 ppt down to 34.5 ppt (two weeks ago) then to 34 ppt. I had thought it had gone lower however it restored to 35 ppt with 1/35 of the salt required to setup tank water, so the lower limit was higher than I thought. So overall a 1 ppt from what I wanted. I put half the mixed water and then waited an hour before adding the other half. I pump mixed water up to the tank, I can turn off the pump and let it syphon back - I used this to take half the mixed water and mix it with another 25 litres of tank water before finally adding it back to the tank.

 

[uhgster1]

Ok, honestly, salinity fluctuations of 1-2 points is nothing to worry about. I thought you had a major 5-10 point drop. Most fish only tanks are around 1.020 to 1.019. We increase it to 1.025 (35) in reefs for extra coral requirements. I have acros and even those have gone through some pretty wicked fluctuations over the years. Don’t stress over exact numbers, you can have coral doing awesome for months and realize that your salinity was at 1.021. Stability is the most important thing. You’re going to hear this over and over in this hobby.

 

[Simon_M]

Agreed, and my Clown and Shrimp are doing fine afterwards. At my (not so local) LFS they have the daily salt in their tanks and temperature. Last time, I noticed the board and they said that (today - then) they weren't updated and off by 1-2 (down). This prompted a talk about their filtration. The Clown is moved up from my QT and I now have two new fish in the QT.

 

[ReefChasers]

Basically if it's 35 PPT +- 3 PPT I wouldn't worry about the shift very much.

 

[damsels are not mean]

Yes just top off with saltwater until you're at 35. No need to complicate it or urgently fix anything.