Reason for 24 hours settling of saltwater

[fijiwigi]

I haven't really understood why the saltwater has to sit for 24 hours with a powerhead before use so I researched. I have been told it needs to become aerated. I googled this article Making Saltwater from what I got from it is it needs to be mixed for 24 hours because freshly mixed saltwater is somewhat caustic (corrosive I think) Like getting salt burn?? once the salt dissolves in the water its not as caustic. From what I assume. the article didn't really state anything about a powerhead for aerating the water. I was thinking I could just keep a powerhead in my RO/DI so the water was already aerated and just let the salt settle for a few hours guess not. I assume the powerhead is really for just helping to mix the salt into the water faster so that it is less caustic. . Just thinking I could mix the saltwater in the AM and do the PWC in the PM but looks like thats out of the question. Just some general thoughts about mixing water. thought I would share.

 

[cmor1701d]

I too have been unable to find any science behind the mix/aerate for 24 hours before use. It may be due to salt mixes that do not dillute well, leaving unmixed traces behind. I don't know that anyone has proved that sw mixed for two hours is any more caustic than sw mixed for 24. The powerhead is more for mixing than for aerating the sw mix. You can do the same by putting anything in the container that would keep the water moving. A powerhead is just the easiest method of doing that.

I really don't see a reason that you can't do an am mix and pm change, but I'm also not going to take that risk on my tank

 

[Hara]

Mix two buckets of saltwater in an identical manner. Leave one sit. Put a powerhead in the other and make sure it is really well aerated (water movement at the top of the bucket). 24 hours later, test the ph in both.

 

[fijiwigi]

PH reasons make sense. My powerhead in my mixing tub is in the bottom of the tub do I need to point the power head toward the top to raise PH?? PH is it really like the oxygen level inside the water? What about freshwater tanks without powerheads is this why their PH requierment is less? would an airstone in a freshwater tank increase PH Just trying to understand things

 

[Innovator]

24hr mixing is called "aging" and allows your mix to fully dissolve and stabilize. Other than Ca, Alk, etc., pH can be a factor in relation to ambient CO2 in reaching a "normal" level (some salts are chemically made up to mix at a higher pH). If you are in a bind, many salts can be reasonably mixed within 2hr time frame.

 

[fijiwigi]

If you are in a bind, many salts can be reasonably mixed within 2hr time frame.

This is kinda what I was wondering. 2 days ago I added some Caribsea aragonite reef sand I rinsed it in a 5 gal bucket with RO/DI water then gently poured into my tank by lowering with a kool-aid type pitcher. My water turned so cloudy I couldn't see anything in my tank. Guess I didn't rinse well enough. it settled after half a day but everytime I move the sand even a little bit the entire tank turns cloudy again. I wanted to do a PWC but didn't mix my water until 8am this morning I work tommorrow and wanted to do the water change tonight.

The other question I have is say I mix my water to a SG of 1.025 but the water was cold after it warmed up I tested the SG and it was 1.020 so if I add 1 or 2 more scoops of salt to the water to reach the correct SG should I wait another 24 hours from that point or would 2 hours beyond that point be ok.

 

[Innovator]

I'm assuming this is for a new tank? When adding new sand, whether pre-rinsed or not, there is always some silt left over. I would gravel vacuum the substrate to remove the actual silt.

If the temperature matches that of the systems water I would add salt if needed.

 

[fijiwigi]

I'm assuming this is for a new tank? When adding new sand, whether pre-rinsed or not, there is always some silt left over. I would gravel vacuum the substrate to remove the actual silt.

Not that new of tank just wanted a nicer sand covering so my shrimp/goby pair would have a nice cozy home when they arrive this week. I think I will vacuum the silt and change about 15 gallons of the total 60gallons volume tonight 10hours after mixing the salt hopefully won't have any issues(PH is 8.2). In the future I need to do a better job of planning ahead.

 

[roka64]

Depending on if you are using a hydrometer or a refractometer, will depend on the readings of salinity. I mixed SW and was testing with a hydro (with cold water) and had hard times getting a good reading. My refracto is able to read at a larger range of temps.

 

[fijiwigi]

Using a refractometer I decided today that I am going to get a heater for the RO/DI container(32 gallon trash can) as well as my heater for the saltwater mixing tub. that way I always have the right temperature water on hand so that I can mix accurately I don't know the scale of SG to Water temp I know that temp affects it.

 

[roka64]

That's exactly the point in premixing. You want to get the pH, temp and salinity the same (or as close as possible) to your main. Kind of like when you acclimate a critter to your tank's parameters.

 

[land locked]

If any one has a conversion table for a refractometer I would love to see it. For the temperature ranges we need.

 

[fijiwigi]

That's exactly the point in premixing. You want to get the pH, temp and salinity the same (or as close as possible) to your main. Kind of like when you acclimate a critter to your tank's parameters.

I could have a container of RO/DI water with a heater and possibly a powerhead and PH that was fine. Adding salt I could get the SG the same after 5min no premixing. Doesn't mean I should add that water to my tank after 5 min

 

[roka64]

Hmmm, I guess it would depend on how much SW you were trying to premix. I use a 32G bucket, so I doubt the salinity (with my well water), temp and pH would come anywhere close to that of my main's.
So if you are talking a small amount of water....say less than 10G you are totally correct (assuming you had a rather large heater, or the ro/di was already warm).

 

[roka64]

Land_locked, I believe that would be determined by the manufacturer. Think of it like thermometers. Some have a +/- 2degree of error, some can have even more or less. The same applies to the brand and grade of error pf the refracto.

 

[cmor1701d]

Almost all refractometers today are ATC (auto temp compensating) so the scale is no longer necessary. I remember seeing one with my original hydrometer.

 

[fijiwigi]

My refractometer is ATC but when I first mix salt into cold water about 60degress it reads 1.025 then after it warms to about 80 it will read 1.020

 

[Kurt_Nelson]

I would guess that has more to do with the original reason for your post, than the temperature. That's the reason I let SW age... not only does it give the pH time to mellow out, it also give the salinity time to even out. Maybe it was just my mixing method, but in the beginning I could never get a consistent salinity until the water had been mixed for 4-6 hours. Now I don't even measure the salinity until 24 hours has passed.

 

[fijiwigi]

I am sure that I am overanalyzing the entire topic I usually let my water stabalize for 24 hours or more and sometimes let it sit for 2weeks and still use it. I just like to understand the why behind everything I do. Its starting to click.

 

[blindskate]

koralia

you should get a hydor koralia, it's a fan that creates air and oxygen and a wave effect in your tank. the more oxygen the better, mine has worked out great!