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Reef Salt Mix - Aquarium Salt Mix Parameters
Last updated on November 30th, 2023
Choosing the Best Reef Salt Mix
When choosing the best salt mix for your reef tank, the brand of salt doesn't seem like a big decision. Most beginners think that all aquarium salt mix is the same, and price is all that really matters. As long as the salinity is the same, there is no difference, right?...
If you keep corals in your reef tank, then you should pay attention to parameters like Alkalinity, Calcium, and Magnesium. What if I told you that your reef tank salt mix could be part of the reason for parameter swings? Reef tank salt mix is much more than just salt, it contains a number of other parameters and elements as well.
If you're not already familiar with the major parameters involved with keeping coral, you may want to read this article about alkalinity, calcium, and magnesium.
What Parameters are in Reef Salt Mix
Reef tank salt mix is much more than just salt, or even alkalinity, calcium, and magnesium. When you do a water change, you are removing 10% or more of the water out of your reef tank, and putting back whatever is in the reef salt mix. Marc (Melev's Reef) lost a large amount of coral from his reef tank, and after multiple ICP tests, he discovered, it was due to low potassium in his aquarium salt mix.
So how many parameters should you worry about? Well honestly, you probably don't need to worry about potassium or really most other minor and trace elements. This was mostly because of a 50% water change with a batch of salt that happened to be extremely low. You are likely only doing 10-20% water changes. Even if the potassium level is slightly off, it won't affect much, unless it is dramatically off like Marc's experienced.
Choosing the Best Reef Salt Mix
As mentioned above, there can be a lot of differences in reef salt mix. In addition to parameters there are differences in price, packaging, if the bags are reseal-able, how much debris is in the salt, and even the "clumpiness" of the reef salt mix. These are not the biggest factors to think about when picking reef salt mix. The factors I find most important in choosing a salt mix for your reef are Alkalinity, Calcium, and Magnesium. This is because whenever you change the water, in addition to salinity, these are the most important parameters to try to keep stable.
Picking the best salt mix for your aquarium depends on the levels you keep in your tank. The best reef salt mix is the aquarium salt mix that is closest the parameters of your saltwater aquarium. This will keep your parameters stable after a water change.
Helping corals stay stable rather than having to re-adjust will help the coral grow and stay healthy. When choosing which parameters to focus on, it's best to make sure you choose an aquarium salt mix with an alkalinity level as close as possible to your tank's alkalinity level. This is the most important of the three main reef parameters to keep stable.
If there are multiple reef salt mix options for your alkalinity needs, choose the one that is closest to your reef tank's calcium levels. Magnesium levels are listed below for reference, but I wouldn't focus on this unless there are multiple options in the correct alkalinity and calcium range. In this case, the reef salt mix with the highest magnesium is the best choice.
Reef Salt Mix Parameters
This table is what I was able to find for approximate parameters when mixing each reef salt mix to 35 ppt (1.026 specific gravity). The table is sorted by alkalinity as this is the most important of these parameters to stabilize. This way you are able to find which salt mix is best for your reef tank.
| Brand | Alkalinity (dKH) | Calcium | Magnesium |
| Reef Crystals | 13.0 | 490 | 1440 |
| Red Sea Coral Pro | 12.2 | 450 | 1340 |
| Coralife | 11.0 | 560 | 1380 |
| Instant Ocean | 11.0 | 400 | 1350 |
| Seachem Reef | 10.0 | 540 | 1450 |
| Tropic Marin - Classic | 10.0 | 375 | 1230 |
| E.S.V. B-Ionic Seawater System Salt Mix | 9.0 | 450 | 1400 |
| hw-Marinemix Reefer | 9.0 | 445 | 1380 |
| Oceanic | 8.5 | 580 | 1650 |
| Kent Marine | 8.5 | 540 | 1200 |
| Fluval Sea | 8.5 | 490 | 1425 |
| Aquaforest Reef Salt Mix | 8.0 | 450 | 1390 |
| Red Sea | 7.7 | 410 | 1280 |
| Brightwell NeoMarine | 7.5 | 413 | 1290 |
| Tropic Marin Pro Reef Salt | 7.0 | 430 | 1450 |
| *Please note that based on the mix consistency and occasional changes by the different companies, these values may change. This was the last known values. If these are not correct, let me know and I will update the table. |
What if my Reef Tank Parameters Change
After settling on a reef salt mix and parameter levels, it is possible for your alkalinity or calcium levels to change. If your alkalinity shifted a large amount, like 8.5 dKH alkalinity to 11.0 dKH, you'll have to decide if you want to maintain the 11dKH or transition back to a lower value. If you are trying to maintain the new levels, simply reference the table above and pick a reef salt mix that closely matches the parameters of your aquarium. If you are trying to lower your alkalinity back to the original levels, just keep using the salt mix you are already using. This way, the small water changes will help bring the alkalinity down over time.
Conclusion
Using the right reef salt mix can maintain your reef parameters and even prevent stressing your coral when cleaning your reef tank. Maintaining as many stable parameters as possible will help prevent coral from dying, and even help them grow faster! Do yourself a favor, pick the best reef salt mix for your tank today!
About the Author
John Krenzer
John is a Software Engineer with a passion for saltwater aquariums, as well as the founder and president of Reef Stable. He started in the aquarium hobby as a child with a 20 gallon freshwater aquarium. His interest in aquarium life grew and in 2008, John set up his first saltwater aquarium.
Today, John maintains an over 300 gallon reef tank system, consisting of a 120g reef and a 210g reef. These large tanks are contained within the same system, sharing a sump as a means to reduce total maintenance and increase total water volume.
John writes articles for the blog as a means to learn about more reef aquarium topics. These articles act as a reference for the readers as well as himself. John updates these articles frequently to provide additional information or make corrections as new information becomes available.
If you would like to request an article, tank tour article, or to collaborate, let me know via the Contact Me Page!
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