Does freshly made saltwater need to sit

I made my first batch of RODI water and now I am going to add salt to it. I was watching a video and it said it needs to sit for a minmum of 24 hours before it can be used... is that true?

 

I don't let mine sit but do have it in the container I make it in with a circulation pump for at least 18-20hrs prior to adding it to my tank.

 

I let mine sit for 24 - 489 hours mixing before I add it to the tank. The only way I won't let it sit is if or when I have a flood I make new water and let it mix for about 2 hours. Then i add the water to my sump(which is where I make my water change from), and let it mix with the old water to dilute if before I turn the pumps on.

 

My Girlfriend works an awesome aquarium only store an hour from me and also used to do Aquarium Servicing.

It's ok to introduce new water soon after mixed provided the PH and Temp are nearly equivilent (or the WC is reletivaly small that they won't effect the Tank).

Something she said that surprised me a lot was that once you mix the saltwater, And it is exposed to Air+Sunlight, and given time bacteria will start to grow very fast. She told me unless my top off water bucket had a lid and was kept out of sunlight, not to use the water after 24 hours.

She takes care of over 300 tanks at work... so I tend to trust her on these things.

 

Well its mixing in my second bathroom currently. I added salt this am. in the video he had the pump going for 24 hours so it's pretty much the same thing you guys are saying. Should I check salinity now or after 24 hours?

 

Check both now and prior to adding it. And as far what was stated earlier, yes Bacteria can grow but only if the water is stagnant (not moving around) and you are not drinking it. I usually add a little salt water bacteria to my mixing pool too. So, Bacteria in the water shouldn't be something that you need to worry about as all aquariums actually need a bacteria culture.

 

How big is your tank? How big is the water change?

Keep in mind the temp difference of the tank vs the new mixed water,

And the aeration is mostly to mix the salt around (aeration from airstones under the water does not introduce oxygen into the water near as much as flow from above coming down into the water ie a filter output above water level ~ but will keep water from becoming stagnant) That said, you can speed up the process by stirring the water vigorously every now and again.

Unless it's a huge huge WC, WC Salinity does not have to match exactly the salinity of the tank... especially if introduced to your tank in a slow manner (gallon now, gallon in an hour, etc...)

 

I really can't say I'm doing this the right way, but when I used to mix my water, I would wait until it turned clear, and that there wasn't any salt residue on the base of the bucket. I didn't have any issues with dying fish, or stressed inverts. Of course, it would all depend on what I had in my tank. All I have are clowns, a rock skipper, star fish, and the CUC, but everything did fine using this method. I now use only natural ocean water for my changes, so no need to mix. Salt is kept on hand if emergencies arise, but only for that.

 

Salt can take up to 24 hours to fully dissolve which is why most people will recommend you waiting that long. What I've seen happen as a result of this is people adding salt until the salinity reads in the range they want, but after 24 hours, it dissolves and is much higher. Do a test mixing where you mix with your aeration and water movement then test every hour after for salinity. The time it takes for salinity to stop changing is how long you should wait.

 

That is probably the most straight forward answer to this question that I have ever read.

What I usually do is wait for the temp to be the same and measure the salantiy then. If it's good, then I add it. Of course i usually keep bottled RO/DI water in 5 gallon jugs right next to my aquarium anyways, so it is already at room temp which is usually in the 70's.