Author Topic: Mixing Synthetic Saltwater for a Water Change  (Read 5601 times)

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Mixing Synthetic Saltwater for a Water Change
« on: March 09, 2006, 04:15:20 PM »
I now a lot of us take mixing saltwater for granted because we have been doing it for so long but on another board I frequent this question has been posed more than once.

1.  Fill a suitable container with freshwater, preferably RO/DI.  If you use city water you will need to add a dechlorinator, follow the package directions for dosage (using extra dechlorinator will not harm anything).

2.  I like to aerate my water for at least 1/2 a day before adding any salt  I usually use a powerhead or extra pump to aerate and mix the salt in.

3.  Add salt to the water, 1 cup to every 2 gallons of water is a rule of thumb for the amount of salt needed but you will have to fine tune the amount later.

4.  Allow the salt and water to mix and aerate for at least 8 hours and then check the salinity level )specific gravity) of the saltwater.  If the salinity level is too low add some more saltmix and allow it to mix until all of the salt has dissolved and retest, if the salinity level is too high add more freshwater (RO/DI) to get the level down to the level you want.

5.  Now that the salinity level is set you need to match the temperature of your tankwater, add a heater or icepacks as necessary to reach the same temp. as your tank.  You should also check the pH of the water and make sure they are the same, as a note some saltmixes may need to aerate for 24 hours after mixing the salt in for the pH to stabilize.

6.  You are now ready to add the fresh saltwater to your tank, remove the same amount of water as you have made up and slowly add the new water back into the aquarium.  Before removing any water remember to unplug your heater and allow it to cool if it is mounted where it can be exposed to air when you remove the old tankwater.  Another thing to make sure you do is to add any evaporation water to your tank prior to removing any water, this may seem like it is a step that could be skipped but the salt in your aquarium doesn't evaporate so your salinity level increases due to the evaporation and if this water is not replaced your salinity level will rise with each water change.

I think that pretty well covers mixing saltwater and doing a waterchange.


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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #1 on: March 09, 2006, 08:17:27 PM »
Unless you are having problems you shouldn't have ammonia spikes, and if there is a problem would be the only time that you would do a water change because of ammonia levels.  Waterchanges are done to try and keep your nitrate level below 20 ppm.  Nitrate is the final product of your normal cycle and frequent partial water changes are a way of eliminating excess nitrate.  You have a great idea in keeping plenty of water made up just in case you need it.  I am not real familiar with Stability and Stresszime but Biospira is actually supposed to be live bacteria (nitrosomas and nitrobacters) to help jump start the tank cycling process.

Offline aquawolf

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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #2 on: March 09, 2006, 11:07:18 PM »
For my 90 gallon reef tank, I do not see any way I could get away without doing my water changes.  I change out 10% weekly, which usually ends up being between 10 - 13 gallons overall.  I do this to keep the nitrates low, keep the ph stable, keep the calcium level stable and so on.  The corals in my tank are utilizing the calcium as calcium carbonate to help make their skeletal structure and to keep growing.  The Caulerpa in my Aquafuge also sucks some calcium out of the water system while helping to lower nitrate and phosphate.

Without doing the water changes, I wonder how long it would be until my calcium level reached nearly zero and my nitrates were off the chart.  This sounds like a terrible situation to me, so how are you able to get away with not doing water changes for a month or more?   :dontknow:

On a side note, where can I find one of those 55 gallon plastic drums?  That is the exact thing I am looking for to use as my RO/DO water holding tank. 

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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #3 on: March 10, 2006, 12:57:33 PM »
I haven't changed water on any of my 3 tanks in, well, a long time :D  But that's another story.

I'm a firm believer in at least topping off with RO/DI and chaning at least 10% to 20% once a month and as needed.

Now slap for not changing my water.

My skimmer gets clogged constantly LOL
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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #4 on: March 11, 2006, 06:17:03 AM »
The SC Aquarium uses local saltwater out of the Cooper River.  The biggest thing to worry about using natural seawater is introducing something like a disease or parasite that is totally foriegn to your fish and they have no immunity.  The Aquarium goes through many different steps in their filtration process to prevent just that.
« Last Edit: April 24, 2006, 10:44:13 AM by skipm »


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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #5 on: March 11, 2006, 10:39:49 AM »
One can filter most anything out of the water, but some of the bio life in natural water is like candy for some of the softies... Try a Mandarin in a regular water environment with live beach sand from Folly Beach.........Had a 10g, Lee skimmer.whisper120 biowheel with fluorescent hood...10# chunk of very active L/R and two in of live beach sand  with crushed shells.   my Mandarin lived over a year in bliss with a banded coral shrimp......................
« Last Edit: March 11, 2006, 10:48:49 AM by dan-o »

Offline Lin

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Re: Mixing Synthetic Saltwater for a Water Change
« Reply #6 on: August 23, 2014, 01:10:19 PM »
Thought many of us could benefit from the above info written many years ago...

Also,  here's a mistake I made when I started mixing my own salt water.
Don't think that just because your salinity is correct that the rest of your levels are.
Every salt mixture and somtimes different buckets of the same brand will show different levels
of calcium , magnesium, kh, etc.
For example, many of us use Instant Ocean salt. For my water changes my mixture is
1.025  for salinity but my calcium level in that mixture is 380 and magnesium is 1080.
So I dose it to bring those levels up.

Share your findings and  questions regarding different salts and mixing

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