Adding salt to established tank

[Injoynit]

I have a few question about salt additions to established tanks.

1. What happens if I just add salt to an established tank and let the tank mix the salt? Fish die? Precipitation? Other?
2. What happens if I mix some salt in a container with RODI water and then just add it to the tank?
3. Why is salt needed to mix at around 78 deg instead of just room temperature or something colder?
4. If I never change the water in my tank but continue to add additives will the salt ever go bad?
5. Lastly, what is the best way to add salt to a new tank and then an established tank?

Just more of less curious for some factual answers as I like to continue to learn as I continue in this hobby. ( I think I know the answers to the above, but I'm only guessing and want to be more informed.)

Thanks..

 

[GaryE]

If you mix it in the tank, with critters in it, there will be a salinity spike that could stress or kill the fish. Even if you premix in RODI and dump it in. If you need to do that to bring up the salinity, do a slow drip, preferably into your sump so that it gets distributed slower.

Mix salt at the same temp as your DT water because it mixes easier and more complete at a higher temp. Plus, you will undoubtedly be adding that water to the tank, so why not have the temp the same.

If you aren't doing water changes, how are you exporting excess nutrients?


If you are mixing salt in a new tank with no inhabitants yet, it's just fine to mix in the tank. Some say not to do it, but if you are going to be doing a 3 to 4 week cycle, it won't hurt anything.

 

[GaryE]

**** NOTE, The previous post is just my opinion and how I do it. Your mileage may vary. ****

 

[Randy Holmes-Farley Verified Community Expert]

I have a few question about salt additions to established tanks.

1. What happens if I just add salt to an established tank and let the tank mix the salt? Fish die? Precipitation? Other?
2. What happens if I mix some salt in a container with RODI water and then just add it to the tank?
3. Why is salt needed to mix at around 78 deg instead of just room temperature or something colder?
4. If I never change the water in my tank but continue to add additives will the salt ever go bad?
5. Lastly, what is the best way to add salt to a new tank and then an established tank?

Just more of less curious for some factual answers as I like to continue to learn as I continue in this hobby. ( I think I know the answers to the above, but I'm only guessing and want to be more informed.)

Thanks..

1. The primary concern is an undissolved chunk of some component of the salt mix landing on a delicate organism and making it locally very high in salinity or other parameter that may injure the organism.

2. This is the way to increase salinity. Use enough RO/DI to be close to seawater salinity. Hypersaline seawater may lead to precipitation of some components.

3. No need to warm it it if you add a small enough amount to the tank at once. Salt stays dissolved better in cooler water, though may take longer to dissolve in the first place. I never heated my new salt water.

4. "Salt" doesn't go bad, but things may accumulate or be depleted that are dealt with by water changes.

5. New tank, you can dissolve in the tank before adding rock or creatures. Existing tank: put normal strength seawater in your ATO, or manual evaporation replacement.

 

[Randy Holmes-Farley Verified Community Expert]

Mix salt at the same temp as your DT water because it mixes easier and more complete at a higher temp. Plus, you will undoubtedly be adding that water to the tank, so why not have the temp the same.

Some things, notably calcium carbonate, are less soluble in warmer water. Some salt companies recommend mixing in colder water.

 

[Rick Krejci]

When I need to increase salinity I just add some salt to the ATO water which usually takes a week to be used up. Very gradual increase.

 

[RonSwanson]

I can tell you first hand what happens if you add one cup of salt to an established DT with fish and coral directly into DT. I didn’t think much of it since one cup would hardly do anything for such a large water volume but I think the issue was salt making direct contact with corals...fish begin to freak out and fight for hiding spots. All the snails fell off the rocks and glass to the bottom of the tank. SPS...well RTN happens....LPS and zoas closed up tighter than my butthole. What a bad decision on my part. Some lessons learned very painfully.

 

[craig_19xx]

I can tell you first hand what happens if you add one cup of salt to an established DT with fish and coral directly into DT. I didn’t think much of it since one cup would hardly do anything for such a large water volume but I think the issue was salt making direct contact with corals...fish begin to freak out and fight for hiding spots. All the snails fell off the rocks and glass to the bottom of the tank. SPS...well RTN happens....LPS and zoas closed up tighter than my butthole. What a bad decision on my part. Some lessons learned very painfully.

Did your stuff recover?

 

[fixmdude]

It depends on the sensitivity of each life form. I added a cup to my sump for an 80g thinking the pump would dissolve it but I could see specs being pumped into the tank. The fish higher up swam sround and were fine. More salinity makes for heavier water. The yellow headed jawfish was the lowest fish in its burrow and maybe the most sensitive. It had trouble breathing and didn’t make it. I never had that problem before but I had a bigger 125g and no fancy sensitive fish like I do now.