How long should mixed saltwater aerate before using?

glb · Mar 6, 2015

I'm trying to improve my aquarium skills and mixing salt mix and RO water is where I want to learn more. I've always just thrown the water and measured salt mix in a bucket and stirred it until it dissolved. Then I would immediately pour it into the tank. I've heard this isn't the best way to do it. Right now I'm aerating the batch I just mixed up with an air stone. What else is good practice when mixing up water. I've just rehabbed my tank and want to learn the best habits possible. Should I let the water sit? Any help would be greatly appreciated!!

mcarroll · Mar 6, 2015

Using ASAP is generally better. I wouldn't change if it was working.

glb · Mar 6, 2015

Well my tank crashed last summer, not because of water changes but a temp spike. I've rehabbed it back to good health and want to get everything in place before I add livestock. It did seem to be working before so maybe I shouldn't rock the boat. Thanks!!

LetItReef · Mar 6, 2015

I mix my salt with a Powerhead, Aerator/bubbler and a Heater. I let it mix atleast 4 hours if I need it asap, normally overnight- Instant Ocean Reef Crystals.

zesty · Mar 6, 2015

LetItReef said:
I mix my salt with a Powerhead, Aerator/bubbler and a Heater. I let it mix atleast 4 hours if I need it asap, normally overnight- Instant Ocean Reef Crystals.

yup, usually overnight or over a few nights. I have such good intentions that happen 3-4 days later... haha

IronVulture · Mar 6, 2015

I recommend reading the instructions on your salt container. Some salts advise against using air to mix some need to sit for a while before you test salinity having a heater is a good practice to bring freshly mixed water up to the same temp in your tank

glb · Mar 6, 2015

Thanks everyone. I live in Miami so temp isn't a problem! What's the benefit of waiting a bit?

glb · Mar 6, 2015

I use IO Reef Crystals btw. No coral in the tank now but as soon as I'm sure things are stable, I'll slowly restock.

Waters · Mar 6, 2015

I use IO Reef Crystals also. I mix everything the night before with a powerhead and heater letting them run all night.

Tapio · Mar 6, 2015

It's convenient to mix a day or two before, but it is ready to go as soon as it has dissolved completely. It is always good to have good water movement in the DT but I assume that is so.

glb · Mar 6, 2015

It is. I have a hydor in there for movement. Does the alk drop at all if the water sits? I had that problem with seawater and stopped using it for that reason.

saltyphish · Mar 6, 2015

The benefit is to allow the salt mix to fully stabilize. I would follow the directions from the manufacturer they should know best.

glb said:
Thanks everyone. I live in Miami so temp isn't a problem! What's the benefit of waiting a bit?

mjs020294 · Mar 6, 2015

I have a 30g tank of ready mixed saltwater with powerhead. I use about 20g a week and top it back off to 30g.

NanaReefer · Mar 7, 2015

I mix for 24hrs, but have gone 48hrs. No heater, room temp, I remove/add via my sump, slowly.

LetItReef · Mar 8, 2015

I recommend get a probe thermometer; new salt mix and current temp of tank atleast similar or close temp readings.

CoralFreak_350 · Mar 9, 2015

The method of using a powerhead to mix and then letting it sit provides several benefits. If you wait a while such as overnight you allow everything to dissolve fully and it ends up not being as cloudy. Plus if there is any impurities such as dirt in the salt it will all be collected in the bottom of the bucket for easy removal. I would also recommend a heater to get it as close to tank temperature as possible. This wont harm anything by adding water that is a few degrees off but you will get the most accurate readings and it will eliminate variables. These are my own personal opinions that work well for me and has never failed me yet.

glb · Mar 9, 2015

CoralFreak_350 said:
The method of using a powerhead to mix and then letting it sit provides several benefits. If you wait a while such as overnight you allow everything to dissolve fully and it ends up not being as cloudy. Plus if there is any impurities such as dirt in the salt it will all be collected in the bottom of the bucket for easy removal. I would also recommend a heater to get it as close to tank temperature as possible. This wont harm anything by adding water that is a few degrees off but you will get the most accurate readings and it will eliminate variables. These are my own personal opinions that work well for me and has never failed me yet.

Thanks! Great advice.

AZDesertRat · Mar 9, 2015

There is no benefit to letting it sit any longer than an hour or so. Any good salt will dissolve almost immediately and the pH will stabilize right away. FutureDoc did several studies a few years ago with many different salts and RO/DI water using very expensive instruments and data loggers and found this to be true. The old days of mixing overnight or whatever are long gone.
I mix and use my new saltwater as soon as the pH, temperaure and salinity approximate the the display. Usually less than an hour unless I need to warm it morein winter months.

jolt · Mar 9, 2015

glb said:
It is. I have a hydor in there for movement. Does the alk drop at all if the water sits? I had that problem with seawater and stopped using it for that reason.

I have found that alk drops around 0.5 dKH every couple of days. This is with regular Instant Ocean stirred with a powerhead. I mix larger batches than I need for a single WC and so I dose alk to match my tank params before I do the WC. I would suspect other trace elements precipitate as well. Probably why folks recommend using ASAP.

gidenski · Mar 10, 2015

I use Red Sea Pro salt. I personally get the RODI water about 48 hours before. Then the night before I intend to do the water change I will start the heater and aerator so everything is the same temp as my tank by the morning. First thing in the morning I measure up the salt and dump it in. Generally it's mixing for about 2 hours while I do all the other maintenance things I do before pulling water out (specimen count/observation, clean glass, change mechanical filtration media, change carbon media). I find that I get a much better feeding reaction from the corals due to the bacteria in the salt mix if I get it in the tank sooner than later.

Good luck with the re-stock. I'm personally recovering from a crash myself (due to KH neglect).