How long can I store saltwater after mixing? | BRStv Investigates


Today on BRStv Investigates, “How long can
you store your mixed saltwater?” Hi, I’m Randy a host for the YouTube series
BRStv Investigates where we take popular reefing theories, methods, questions, & products and
dive even further than what the manuals and packaging will tell you; in order to put them
to test in real world environments; rate them on our scale of reef fantasy to reef certainty
and share with you, the reefing community, what we find. Today we continue our testing of some of our
most popular salt mixes, by answering the common question of, “Will Alkalinity and
Calcium levels in freshly mixed saltwater drop or precipitate during storage?” Meaning that if I chose a specific salt brand
based on the levels for Alkalinity and Calcium they provide after mixing a batch to my target
salinity of 1.026 Specific Gravity or 35parts-per-thousand; how long can I store that batch of saltwater
and trust that those levels won’t shift to the point that I would need to adjust them
back? So, for those reefers who are making small
batches of water and using it rather quickly after mixing, worrying about the Alk and Calcium
parameters shifting is likely less important to you. However for a growing number of reefers who
like to mix larger batches less frequently and use over longer periods of time or for
those who are using stored saltwater in auto water change bins, it would definitely be
nice to know if your salt mix’s Alkalinity and Calcium were stable from beginning to
end. In order to determine just what happens to
mixed saltwater over time during storage, we plan to test the same eight most popular
salts on our site that we used in our test for cost per gallon; with the Tropic Marin
Pro and Classic; Brightwell NeoMarine; Red Sea Coral Pro and Blue Bucket; HW Reefer;
and both Instant Ocean Standard salt and Reef Crystals. We’ll mix up 20gallons of each salt brand
to the most commonly targeted 35parts per thousand or 1.026 Specific Gravity; and take
their initial batch readings immediately after mixing, two hours later, four hours later,
at a full 24 and 48hrs, and also at the 1, 2, and 3-week storage mark. In order to remove outside variables like
temperature and water circulation, we plan to only mix each batch of saltwater until
they are visibly clear at a room temperature of 67-degrees, then leave them loosely sealed
without further circulation and heating …much like storing the saltwater at room temp in
a loosely sealed container like a Brute Trashcan with a lid. The biggest thing to note here is that for
these tests we are using the same type of hobby grade test kits that many reefers also
use at home, so there should be some expectation of accuracy margin with their results which
will probably be in the plus/minus 1/2-a-dKH point for Alkalinity and about plus/minus
10-15 parts per million in calcium. This accuracy range and margin for error are
within the test kits accuracy range with some added room for minor procedural inconsistencies
and subjective endpoint readings and due to that we’ll likely see some type of fluctuations
in the results, but I expect the answer will still be clear regardless and end up providing
us with a window into some of the same readings you would get at home, using the same test
kits and procedures. Let’s start looking at the results of this
test by starting with the changes in Calcium for each of the eight salt mixes, which as
you’ll see don’t really tell a jaw dropping story when looking at the overall change for
each salt and most are within our plus/minus 10-15 part per million testing margin and
some even tighter than that. Again, I’d note that this is a hobby grade
test kit that uses a color change indication as to the concentration levels in the sample,
so we do have to reasonably expect that the end point is going to be subjective based
on methodical testing procedure and individual interpretation of the exact moment the reagent
causes a full change in sample color. Before we get too far into the results, I
wouldn’t expect to see a substantial drop in Calcium due to precipitation, because calcium
is more abundant in the water column versus Alkalinty to the tune of about a 7 to 1 ratio. Meaning that for every change up or down in
one full dKH point, on average the Calcium would only change about 7parts per million…so
pretty insignificantly in comparison and likely why Alkalinity will be the more determinative
factor when showing swings throughout the duration of storage. Starting with the Tropic Marin Pro results
we see that immediately after mixing we get a start point at 400ppm and at the end of
three weeks in storage it ends just 10parts per million from that start with a reading
inside of our 10-15ppm margin range of 410parts per million calcium. The average of the readings ends up being
413ppm and what I would consider to be a negligible or zero change. The Tropic Marin Classic salt ended with similar
results over three weeks, with a starting point of 400parts per million and ending at
415 and still within our margin for error for hobby grade testing. Along with that and similarly to the Tropic
Marin Pro we see an average of only 411, leaving this salt pretty much unchanged over the entire
testing period. Brightwell NeoMarine is up next and again,
we see a pretty flat set of results starting with 390ppm calcium and ending at 400, with
the overall average coming in at 393 which is only a surprising 3parts per million deviance
from the start point. HW Reefer showed slightly different results
than the previous three, testing at 450ppm right after mixing and ending 25parts per
million lower after three weeks at 425; which is about an overall drop in calcium of 10parts
per million when factoring out our 10-15ppm margin of error and pretty darn close to being
another salt mix that seems to hold steady over time. Let’s take a look at the Red Sea Blue Bucket
next, which tells a similar tale to the previous salts with a 400 start point and 410 end point,
for an overall deviation of less than our margin of error. The overall calcium results are pretty close
to identical as the Tropic Marin Pro in starting and ending points, as well as an average of
the same 413ppm throughout the testing period. Red Sea Coral Pro is next and right away we
notice the first pretty noticeable drop in calcium where right after mixing we see an
initial reading of 495 and after three weeks an endpoint leveling out around 430 for an
overall change of 65parts per million. The largest difference in calcium comes within
that initial 4hrs with a fall from 495 to 440, and given that Coral Pro is absolutely
an elevated salt mix it’s probably not surprising to many reefers that with elevated levels
of Alkalinity and Calcium both, we see some noticeable drop due to precipitation shortly
after mixing and also likely why Red Sea themselves recommend mixing for 30mins to 2hrs, but no
more than 4 total. The results for Instant Ocean Standard are
roughly on par with a majority of the other salt mixes tested, with a 400ppm start point
and a 385 end point, which gives it an average of 387 parts per million and the lowest overall
calcium level out of the group, likely due to the two relatively low readings that came
in at 375parts per million. Rounding out the Calcium testing is the Instant
Ocean Reef Crystals that states has purposely elevated Calcium levels and shows in the testing
where it started at 500parts per million and ended 10ppm lower at 490, with an average
across all points at 489. Moving on to Alkalinity, where we’ll likely
see a clearer picture as to how each salt holds up to storage as changes in dKH are
more noticeable over Calcium likely due to its lesser availability in the water column
where more subtle changes should be easier to see. Again starting with Tropic Marin Pro we see
almost a completely flat line over three weeks of storage with the Alk starting at 6.9dKH
right after mixing and only fluctuates a maximum of 3/10ths of a dKH point throughout the entire
test, which is well under our 0.5dKH testing margin. Tropic Marin Classic shares a somewhat similar
path beginning with 8.9dKH Alkalinity and ending 2/10ths higher at 9.1. The largest swing overall was a difference
of 0.6dKH from the lowest test at 8.6 to the highest at 9.2, but when we factor in the
1/2 dKH point for testing margin, the overall change comes out to only a 10th of a point
and not really any significant change at all. Much like the calcium test, Brighwell NeoMarine
looks to have the least amount of overall change, with a starting point of 7.7 and an
ending point of 7.8, and throughout the entire 3week period only changed in Alkalinity by
a pretty surprising 2/10ths of a dKH point. HW Reefer wound up being another well performing
salt when it comes to maintaining parameters through storage where it starts at an 8.7dKH
and ends just a tenth higher at 8.8. Much like the Tropic Marin Pro, the overall
change from HW’s lowest to highest reading is only 3/10ths of a dKH. Let’s take a look at the Red Sea Blue bucket
salt mix which shows a slight drop in Alkalinity from its starting point of 7.9 to the end
point of 7.3. We do see a slight increase peak at the 48hr
mark where it hit 8.3dKH, which is difficult to explain but still within our 0.5dKH margin
of testing, but does come back down after 2weeks of storage and ends with a 0.6dKH difference
from beginning. The Red Sea Coral Pro again shows the largest
change across the salts we tested with the highest start point of 11.0dKH and ending
with a drop of 2.2dKH total at 8.8dKH. Again we see a slight increase at the 48hr
mark as we did with the Blue Bucket, but as for the drop of alkalinity in general, I’d
say that this is actually the type of performance that could be expected from elevated levels
where the water is super saturated with Alkalinity and Calcium which probably should fall over
time and likely why Red Sea openly provide very specific mixing instructions where you
mix the salt unheated at around 68-degrees and for 2hours at max (absolutely no more
than 4hrs), then heat to match tank temp then use making it a good option to use in a shorter
period of time. Looking at Instant Ocean Standard again we
another salt with slightly elevated levels of Alkalinity, which starts at 10.1dKH immediately
after mixing and ends surprisingly higher at 10.4 or 3/10ths higher. Overall, from the lowest reading of 10.1 in
the beginning to the highest of 10.6 at the 2week mark we see a 0.5dKH increase, which
is within our testing margin, but still hard to explain. Similarly to the Red Sea Coral Pro the Instant
Ocean Reef Crystals shows purposefully elevated levels for Alkalinity and Calcium, however
for the Reef Crystals the Alkalinity doesn’t fall but actually also seems to increase over
storage (much like the IO Standard did) from a start point of 10.6dKH to an end point of
11.0. Again it is hard to explain how the levels
can climb, although it is within our testing accuracy range, but both Instant Ocean salts
performed remarkably similar to each other with their levels increasing. Even harder to explain is how Reef Crystals
is able to maintain higher Alkalinity and Calcium without any type of measurable drop
in both parameters that would indicate precipitation. Ok, so to answer today’s question of “Will
Alkalinity and Calcium levels in freshly mixed saltwater drop or precipitate during storage”
I’d actually rate this one 2 on the reef fantasy scale because it is pretty obvious
to me that really most of them can be stored without issue; especially if left uncirculated
and unheated as we did. Really the only outlier here is the Red Sea
Coral Pro salt, which seems to follow the expected path of results that one would guess
when using salts with purposefully elevated levels, yet I believe Red Sea would recommend
not storing it for longer periods of time. Alright, what does this mean for the average
reefer who’s looking to make larger batches of saltwater that will be used periodically
for smaller percentage water changes or in an Auto Water Change situation like we use
here at BRS for our BRS160, Reefer 750XXL and Ryan’s office tanks? Really based on the storage conversation alone,
I’d be comfortable picking most of these salts and know that I can expect the same
levels from the time it was initially mixed to the time I finally got around to using
it or while it is being dosed slowly over a longer period of time from my auto water
change reservoir. As long as we are able to mitigate evaporation
by keeping my reservoir loosely closed and likely out of large temperature changes, pick
salt that matches your desired perimeters and it will likely hold for you. So what’s next in salt testing BRStv Investigates
episodes? Well for those who require larger percentage
water changes where, not only are matching parameters for Alkalinity and Calcium of their
display tank important, but also matching the temperature to reduce a larger fluctuation
being equally as important; we plan to take this test even further by running the same
experiment, but in a temperature controlled tank at 78-degrees with the addition of circulation
to find out if and how heat and flow affect the same Alkalinity and Calcium parameters
for each of these salt mix brands, in an effort to determine whether some these are cleaner
than others or more or less likely to precipitate crust in the tank? Lastly, this wouldn’t be the regular Friday
BRStv episode without something to give away; so this week we have two Hanna Instruments
Professional Reef Test Kits up for grabs, each valued at 230-bucks, so click that link
in the lower left or head over to the site and click free prizes to sign up to win. Finally, head on over to our Reef2Reef post
and vote on today’s poll asking, “How long do you store your mixed saltwater?” I’m interested to see if some decide to
start storing theirs a bit longer. Stay tuned as we continue to explore and test
even more reef myths and reef certainties around salt mixes and if you have anything
you’d like to see us test or questions about salt mixes in general, drop a comment below,
share your ideas on our reef2reef thread, or better yet jump on our #AskBRStv FB group
where the BRS crew including Ryan and I get in there and answer your questions. See you on the next BRStv!

Comments 87

  • Finally…….

  • Thanks guys! 😉

  • Thanks guys

  • Thank you very much for doing these tests!

  • Generally when I store my water I have a heater to keep the saltwater at the same temperature as my tanks. Do you guys always keep your mixed saltwater at room temperature or is it alright to keep it at 78 degrees after mixing?

  • Anyone else notice the line was on 1.027 specific gravity

  • I've been using red sea blue and coral pro and I love them. But after this i may try a bucket of the brightwell. It seems very stable

  • I always wonder this, thanks for the research!

  • You’re doing god’s work.

  • Always coming through with the useful information. Thanks guys!

  • Time to make bigger batches of saltwater, been waiting for this info.

  • You should try keeping the power heads on so they're constantly mixing the whole time. I have made salt water and kept it for 2 months with just the the power head mixing the water in the bucket with the lid in

  • So just to confirm your just mixing the salt with a power head and after mixing clear removing the power head so no circulation in the storage container?

  • AWC..a month at a time

  • Every time I have a question you guys have a video to answer it. You guys are one of the greatest resources in this hobby. Thank you for all you do.

  • That sure explains a lot! I have used Red Sea Coral Pro salt for years and have always mixed a batch on Friday for use the next Friday. I think I may have to rethink my approach to mixing and storage (or switch salt mixes). Thanks for the very informative video – keep up the good work!

  • You should run the same test but keep the water heated to 78 and constantly mixing with a small powerhead to see if the results change.

  • Please make a dinoflagellate video. Many people suffer from this terrible pest

  • Great video ! Looking forward To the next big Test ! Ever since I 's was a baby I' s always be wondering

  • how is it with magnesium

  • Guy turns to his coworker who uses Red Sea over Instant Ocean and says “your salt sucks lol”.

  • Great video! But when will you have a distributor in the uk?…. I’m sure with your reputation that it would be a great international business, Happy to talk about a franchise deal 😉 wink wink

  • You are fuxking awesome

  • Nice video randy! Any reason to think the tropic Marin bioactif would be different than the two you tested??

  • I’m a bit ‘salty’ you didn’t do Fritz too

  • I don’t understand how mixing it for more than 2 hours could be bad.

    When it’s in the tank it’s being continually mixed just the same through flow.

  • Red Sea has proven to be junk… every single test exposes more shortfalls for that brand. Instant Ocean, typically the beginner salt did surprisingly well.

  • You seem to have a hard time understanding measurement error of the test kits. You repeated talked about the 'expected range of accuracy,' but then in the next breath said you couldn't understand how the levels could rise. Assuming complete dissolving of the mix, Alkalinity & Ca should never rise. The only explanation is the measurement error of your test kits.

    Also, Mg is critical to the stability of Alkalinity and Ca in solution. Measuring Mg levels would likely help explain how the Reef Crystals maintained higher levels and how the RedSea pro mix tended to drop.

  • Im using RC…i have been seeing a drop in dkh but my water is heated at 79 and circulating….after being mixed should i stop the pump and heater?

  • If RSCP loses Ca levels because of precipitation after 4hrs, why doesn’t this also show up in the Alkalinity (at 4hrs)? Or is it not calcium carbonate?

  • wow…. note to self, if going to start storing water for water changes….. don't use Red Sea pro

  • You guys are amazing!!!!

  • Awesome video, answered several questions I’ve had for a long time

  • Would you expect Fritz regular and high alkalinity salt mixes to be closer to any one of the tested mixes in particular? Thanks again for another great informative video!

  • Really awesome information I always wondered about! Thanks!

  • You are doing a magnificent job. Thanks for the info. I am very pleased with the IO results.

  • I really appreciate these test vids. Thank you for them!

  • dislike because no fritz salt

  • Can you add ph numbers in this test though? Pretty crucial for us nano guys. Thanks.

  • Great topic. Thank you for exploring this question.

  • With honest.. The question is not if alkalinity or calcium will stay stable over a longer period. Check all the other elements by icp from the beginning and the end. I guess a lot of those will change much more than CA and kh.

  • Wish AquaForest was included

  • I’ve used reef crystals for 15 years, it’s the best.

  • Wow, that’s very useful information, because I’m using Red Sea Coral Pro. And I’ve switched from Reef Crystals. Looks like Reef Crystals is not that bad at all!

  • No Aquaforest salt …. feeling lonely here ☹️

  • The highly rated Tropic Marin's Pro Reef salt's 7dkh is on the low side is it not????

  • Thx for all of your videos( I think)!? Ever since I started watching, my life has changed. You can’t see the bottom of my pool because of the great algae growth in it. I have not mowed my lawn and have pile of letters from the HOA. My wife doesn’t even bother me to fix anything on the house any more, as a matter of fact, I haven’t seen her in nearly 2 weeks. I don’t know if that is because I stare in to my aquarium for hours on end, or she has moved out. I guess since I don’t have any money to go to dinner and a movie now or even want to. Yep I just looked, her closet is empty. The time I save now not having to wash her car, I can now spend making water changes. I am certain I will get fired if I leave early one more time from work because I have to see the new shipment of corals before anyone else can see them fresh out of the box. But, I have that covered, I already gave them my application to work there. Of course I will have to downsize my house and truck but get a bigger aquarium. I am hooked Thanks again. Lol
    P.S. if anyone has pictures of my wife please send to me, the corals I know have erased my memory.
    And baby if you happen to read this. I am just joking, I am not downsizing my truck

  • Surprised fritz rpm salt wasnt one of the tested salts.

  • Just curious but what salt brand does BRS use?

  • Include seachem in next test please

  • i Would love to know the impact on PH as i stopped storing due to the PH dropping after 24hrs with the Tropic Marin, will you be showing this in the next test?

  • Again. For the millionth time. I've learned something new every day. Ive been using reef crystals for over a decade (was recommended by a fellow reefer from day one tank build). I never even once considered that salts could be so different and I've never tested a fresh batch of water other than TDS and salinity (i just trusted it i guess). My tank is and always has had awesome mag and alk reading needing little to no dosing whatsoever. Calcium however is regularly well over 500 in my tank though. Now I know that its due to it being 500 right off the bat (WHYYYYY WOULD ANYONE WANT THAT? lol) and my addition of kakl to keep the ph at 8.2 ish is whats causing it to be so high. Not to hijack the post but 1) is 525 simply too high for calcium in a mixed reef with some sps (the coral seem to be doing fin but could obv be better)? and 2) how hard is it to change salt brands without screwing up the tank?

  • Absolutely crucial! Great test guys. I found out the hard way that RSCP cannot be stored longer than a day or two while heated and circulated.

  • Looking forward to the next one!

  • BRS should do a whole tutorial with Aqua forest products with a SPS tank. Demonstrate all Aqua forest tanks like NP pro, salts etc. Some aqua forest tanks really do great

  • Great info as always. How about a video on mixing/storage stations. both ends of the spectrum as a basic home owner station and an extreme gear junkie station. Very curios about your retractable hose, water delivery set up you have. where'd you get it, and how easy was it to change out the hose and connections to reef safe material etc. thanks again for all the great info, keep up the good work.

  • Definitely the best reefing channel on YouTube keep up the good work😏 it's a shame you don't do sipping to the UK the shop here are no where as good as the us did try to buy loads from you website to realise you don't shipping to the UK absolutely gutted do you think they will change it in the near future?

  • What are the parameters that you strive for in a reef tank

  • Great info ! Thanks

  • I’ll never use Coral Pro again after watching this

  • So with the Red Sea coral pro bucket you can only store this for 4 hours after mixing ? So am guessing I won't be able to set up s automatic water changing station ?

  • I have been using HW Marinemix for 4 month now since the new system received water. I tested alk, Cal and mag for the first time last week as I'm planning on trying some test corals soon. I was shocked to see alk was at 6dkh when my target was 9. I tested my saltwater mixing container and it tested at 6dkh. I dumped the water and started a new batch. It was spot on at 9dkh. I'm going to test every other day to find the drop off point. However I do believe HW Marinemix is dropping at some point. I have also found other threads confirming the same. I do use a strong power head and heater. Question if I had 10 gallons left of sw and added 30 gal of fresh water to the 10, then added salt could this be affecting the dkh and Cal? Cal was also low by 50ppm. 450 is what I should be getting but redsea found it at 400.

  • I am starting a 20 gallon saltwater tank. I have experience with saltwater fish and corals. What would you recomend for lifestock.

  • Its my understanding that additives in the salt mixes help with solubilization, this may explain the increase in dKH for some mixes. No problems here storing normal Ca/alk salt mixes for weeks 🙂

  • Glad I never changed to red sea salt mixes.

  • HW-Marine Mix FTW!

  • Were you mixing the water while it was stored or was it sitting stagnant? Heated?

  • Damn, I just switched my 40 gallon tank to Red Sea Coral Pro…going to take a long time to finish that bucket. Wish this was sooner, oh well next time I'll buy reef crystals so I can store the saltwater for 3 weeks.Great vid!

  • Next, wonder how long can plain RODI water be stored?

  • Great episode once again and thank you for doing this for us hobbyists. It would be great if you guys can include Aquaforest Reef Salt in this episodes as well just a thought. Thanks.

  • Another variable in the equation is concentration of CO2 in the air and the gas exchange between air and water. I have experienced more extreme alkalinity reduction over time using both red sea coral pro and red sea blue bucket when stored at warmer temperatures without constant mixing.

  • How long does salt have to mix before adding to my tank. I have been told to mix at temp for 24hrs before adding to tank? Thank y’all so much!!!

  • Ohh man, so disappointed, you should have monitored the salinity too!!!

  • So reef crystals is the best…

  • Maybe test that purple up coraline algae stuff . Ryan got bugs once seeding from another tank

  • Just wondering how would it affect it if it would be stored heated and some circulation?? And could you include aquaforest reef salt in your tests ??? Thanks for great work guys ..

  • I appreciate the testing. BUT your graph is not accurately created. The storage duration line needs to have equal variables of time. So beginning 1 wk 2 wk 3 wk 4 wk and so on. Not 10 min 2 hr 4 hr then jump to 24 hours to a week. Doesn’t make sense to make a graph like that because it looks like it drops off suddenly as opposed to it taking a week to get to that point.

  • Also I’m really confused as to why we are testing this. I figured it was a given that if a container is sealed nothing could leave the container..

  • Who cares? Not me

  • the calcium builds on the side of the walls of the container and then the alk goes up i guess…

  • Has anybody done this on AQUA FOREST SALT?

  • Why does red sea say to mix for 4 hours max if you proved it takes 23 hours to completely mix?

  • will switch from the blue bucket to neomarine red sea got to pricey now.

  • To those who say I’m cheap using reef crystals, told you!

  • in storage do you constantly keep it mixing with a power head or do you mix it a few hours, store it, then remix it before use?

  • I used io reef crystals for yearrrrs but recently switched to red sea coral pro and I'm sold on it after a couple months 100%. You definitely cannot store it for long, it builds up a crud but if used the day after it's great. My fish and corals instantly approve 😁👍

  • The biggest problem would be salinity which if that swings will cause precipitation.

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