What’s the best reef salt mix?–Hands-down, this is the most debated question in the community.
Reefers live and die by which salt mix they use. But, with everyone claiming their choice is the number one, how do you determine which is the best for you?
Well, that’s exactly what you’re about to learn.
In this article, I’m going to explain exactly how you can determine which reef salt mix is the best for you.
Quick Overview of The Aquarium Reef Salt Mixes Reviewed
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
How to Pick The Best Reef Salt Mix for your Aquarium
Here’s the brutal truth when it comes to picking the best reef salt:
Every brand is going to claim to have the best, the most pure salt mix, the best ratio of trace elements, and the best mixability etc.
Now, what you’ll find if you ask on any forum, is different hobbyists swear by different salt mixes.
It’s true, some salt mixes are superior to others. However, when it comes to high-quality mixes, the quality is debatable–there’s no one-size-fits-all.
Therefore, this is what you need to look at:
- The big three: Calcium, alkalinity, and magnesium
- Cost per gallon
- What’s living in your aquarium?
The Big Three
These are the three most important components of your salt mix: calcium, alkalinity, and magnesium. The better salt mixes are going to have higher levels of each of these.
But, before we get into talking about the big three – calcium, alkalinity, and magnesium – what exactly is salt mix, and why do you need it in your reef tank?
The answer is that adding salt mix to your aquarium provides the elements found in natural seawater that would otherwise be missing from your aquarium.
Although seawater is known for its salt, it contains a lot more than just sodium chloride – standard table salt. There are a number of other salt crystals dissolved in as well, the most important of which are calcium and magnesium.
Seawater also contains a large amount of dissolved bicarbonate – the same stuff that’s in baking soda – in order to buffer the water against any sharp changes to its chemical composition that could endanger your fish and corals. Seawater mixes typically refer to bicarbonate as alkalinity.
As a result, the best salt mixes are going to have high levels of calcium, alkalinity, and magnesium.
Calcium: Used by corals and invertebrates to help build their stony skeletons, the recommended concentration in a reef aquarium is 400 ppm (parts per million).
Alkalinity: Alkalinity is related to the amount of bicarbonate in your water and is important because unlike pure water, natural seawater has a pH somewhat higher than 7 – it’s somewhat basic.
Without alkalinity added in in the form of bicarbonate, your tank’s water will be acidic enough to dissolve corals’ skeletons and poison fish. The recommended range for alkalinity is 8-11 dKH.
Manufacturers typically measure alkalinity rather than bicarbonate for a reason.
Both calcium and magnesium add alkalinity to the water, so the amount of bicarbonate that you need in your salt mix can vary a lot based on how much of these other chemicals are in the mix. Measuring total alkalinity makes it easy to find a salt mix that will provide the right chemical conditions for your reef tank.
Magnesium: Magnesium is a trace mineral in natural seawater, meaning that it is found at extremely low abundances relative to chemicals like sodium, chloride, and calcium.
However, magnesium is extremely important for keeping alkalinity balanced – it interacts with bicarbonate to prevent it from precipitating as calcium carbonate, which would quickly remove much of the salt and alkalinity you added into the tank.
The recommended rage in a healthy reef tank is 1250-1400 ppm.
Pro tip: Most salt mixes come with calcium, alkalinity, and magnesium in the proper concentrations for a healthy reef tank, so you don’t need to purchase any salts separately.
Cost Per Pound
Once you’ve looked at the ‘big three’, the next point is to work out which is the best for your money.
You want to look further than just the cost per box.
Look at the cost per gallon.
You do this because all of the major brands tend to have the vital components covered.
Now, the standard box of salt could make anywhere from 150 to 200 gallons of saltwater, depending on the manufacturer. So it can be a bit tricky to determine which is the best for your money.
This is what you can do.
Take the price of the box and divide it by the number of gallons per bucket. Here’s an example:
Brand A costs $40 and can make 200 gallons of saltwater. 200 divided by 40 gives you a total cost of $0.20 per gallon of water.
Once you do this, it becomes much easier to work out how much you’re getting for your money.
What’s Living in Your Reef Aquarium?
Do you own a fish only tank? How demanding are your corals? These are the questions you need to consider.
And here’s why:
While reef salt mixes are largely similar, they contain slightly different amounts of calcium, magnesium, and alkalinity. Some reef mixes have higher concentrations of salts, while others have higher or lower alkalinity.
If your setup contains hard corals, you’re going to benefit from using a salt mix with higher levels of vitamins and trace elements.
Alternatively, if you’re using soft corals or a fish only tank, you may not require the extra benefits.
It’s also important to think about the total alkalinity that a reef salt provides. Hard corals will do better in higher alkalinity environments, while that added alkalinity may actually be worse for soft corals and fish.
Now, I’m not saying you definitely need the extra nutrients, as you can make up for it by dosing. It is possible to buy individual calcium and magnesium salts, as well as specific vitamin and trace element mixes that you can add to your reef water above and beyond the salt mix.
However, if you’re not the most experienced reef keeper it might be best to go with one that is designed for the type of corals you keep.
What’s the reasoning behind this?
Hard corals are constantly using both calcium and carbonate to build their skeletons, which sucks out both calcium and alkalinity from your tank’s water.
If the levels of nutrients in your tank are already low, the growth of coral skeletons can be enough to upset the chemical balance in your tank.
In addition, corals’ ability to grow depends a lot on the concentration of nutrients like calcium and bicarbonate. The lower the concentrations of these skeleton-forming chemicals are, the more difficult it becomes for corals to grow and remain healthy.
This is not nearly as much of an issue for soft corals as for hard corals since soft corals only produce a small coating of calcium carbonate skeleton to retain their shape.
In a tank that only contains fish, the balance of alkalinity is far more important than the exact concentrations of calcium and magnesium since fish can form calcium skeletons at much lower calcium concentrations than corals.
More Considerations
Beyond salt concentrations and alkalinity, there are a few things to think about when choosing a reef salt mix.
Some reef salt mixes are better at storing for long periods without going bad. If you have a small tank or only change the water infrequently, it may be necessary to purchase reef salt mix in smaller quantities to make sure it stays fresh.
In addition, watch out for different reef salt mixes that can alter the color of the water in your tank. While this won’t harm your fish and corals, it can make it difficult to see other pollutants in your tank and alter its aesthetics.
Best Salt Mixes For Reef Aquariums Reviewed
Now you understand what to look for when deciding which salt mix is best for you, you’ll be able to use the comparisons below to make a more informed buying decision about which one is right for you.
1. Instant Ocean Reef Sea Salt Mix
Features:
- Calcium: 400 ppm
- Alkalinity: 11 dKH
- Magnesium: 1320 ppm
- Size: 200 gallons
- Recommended Gravity Range: 1.020-1.026 at 77°F
- 1.4 lbs of Reef Crystals creates 5 gallons of saltwater at the recommended range
One of the most popular choices among hobbyist, due to it providing the required elements at an affordable price.
It is best used with fish only tanks or tanks using soft corals. You can still use this one with more demanding corals. However, it would require extra dosing.
Pros
- Contains the required elements
- Low cost per gallon
- Consistent results
- Ideal for fish only reef tanks
Cons
- Slow to dissolve, may cloud your tank for a bit
- Not ideal for demanding corals
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
2. Instant Ocean Sea Salt
Features:
- Calcium: 425 ppm
- Alkalinity: 14 dKH
- Magnesium: 1440 ppm
- Size: 200 gallons
- Recommended Gravity Range: 1.020 – 1.024 at 77°F
- 1.5 lbs of Instant Ocean creates 5 gallons of saltwater at the recommended range
The second from Instant Ocean, this one is an excellent option if you run a reef tank with more demanding hard corals.
It contains higher levels of calcium to help stony coral and coralline algae grow.
Extra trace elements will provide nutrients and vitamins to support the health and growth of your corals, anemones, and other invertebrates.
Pros
- Contains the required elements to support demanding corals
- Affordable
- Dissolves quickly
- Helps to neutralize trace heavy metals often found in tap water
- Comes in a package of 4 separate bags which keeps the salt fresh and prevents it from clumping
Cons
- A few users have reported a brown residue
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
3. Red Sea Fish Pharm ARE11230 Coral Pro Salt Mix
Features:
- Calcium: 465 ppm
- Alkalinity: 12 dKH
- Magnesium: 1390 ppm
- Size: 175 gallons
Although nearly twice as much as the previous two, Red Sea Coral Pro gives you an excellent balance of the major elements needed for a healthy environment.
Containing no heavy metals or organic binders, this one is best if you’re keeping hard corals and invertebrates that will benefit from the extra trace nutrients provided.
If you’re keeping a heavily stocked aquarium, and you find yourself having to constantly replace nutrients, this is probably the salt mix for you.
Pros
- Ideal for heavily stocked reef aquariums
- Provides lots of nutrients
- Fast dissolving
Cons
- More expensive
- Extra nutrients not necessary if you have low stock or fish only tank
- Many reporting the box arriving damaged (no damage to salt)
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
4. Kent Marine Saltwater Aquarium Salt Mix
Features:
- Calcium: 550 ppm
- Alkalinity: 10 dKH
- Magnesium: 1450 ppm
- Size: 200 gallons
Popular because of how fast it dissolves in water without clouding it.
At a glance, it contains all of the elements needed to promote healthy coral. However, a number of users have reported having low calcium and magnesium once mixed.
One big positive is that this salt won’t affect the alkalinity or pH of your water.
Again, if you’re keeping hard corals and want them to grow fast, this is one you should consider as it uses Cora-Vite technology.
Kent Marine claims this gives your corals an unmatched marine environment.
Pros
- Affordable
- Suitable for hard corals and fish only tanks
- Fast dissolving
- High growth rate for corals
Cons
- May have inconsistent results regarding nutrient balance
- Some users claim the salt arrived hard as a brick
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
5. Brightwell Aquatics ABANMAR150 Neomarine Marine Salt
Features:
- Calcium: 420 ppm
- Alkalinity: 11 dKH
- Magnesium: 1380 ppm
- Size: 150 gallons
If you battle with magnesium levels, have pH issues, and/or run a ULNS (Ultra Low Nutrient System) and don’t want an Alk spike, you should consider this product.
It’s a very popular American brand with experienced reef hobbyists, with many reporting to have excellent results.
Brightwell have precision-formulated and extensively researched and tested over many years to attempt to replicate the natural ratios of the oceans major elements.
This mix provides consistent results and is suitable for hard and soft corals.
Pros
- Provides an excellent balance of nutrients
- Ideal if you struggle with magnesium levels or pH issues
- Fast dissolving
- Ideal if you run a low nutrient system
Cons
- More expensive per gallon
- Some report it having a bad smell
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
6. Seachem Vibrant Sea
Features:
- Calcium: 425-445 ppm
- Alkalinity: 8.4-11.2 dKH
- Magnesium: 1250-1350 ppm
- Size: 220 gallons
- Recommended Gravity Range: 1.020 – 1.025 at 75°F
Seachem has discontinued their previous high end reef salt mix (creatively named “Reef Salt”) and replaced it with their new product, Vibrant Sea.
It is designed to contain all of the essential compounds needed in a reef tank, all in one mix. Vibrant Sea is also more concentrated than other mixes, allowing you to get more saltwater while using less salt mix.
The idea is that you can simply mix up your water, and it will already have all of the major, minor and trace elements that your corals need, eliminating the need to constantly add other nutrients.
Seachem also claims that, since their product is so highly soluble, you can mix it up and use it on the same day.
Many users report that they saw significant improvements in coral growth and color when they switched to this salt mix.
But, there have been some reports that Vibrant Sea can raise alkalinity to undesirable levels if it’s used for large water changes on small systems.
Pros:
- Contains all needed reef nutrients in one mix
- Can mix and use the same day
- Increased coral growth
Cons:
- Some report it’s not great for frequent, large water changes
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
My Top Pick
Lets be real.
None of these salt mixes are going to cause your reef tank any harm.
However, the truth is, every setup is different–it’s why many people love the hobby.
And guess what… even if you buy the most expensive salt mix, if you don’t keep on top of regular 20-25% water changes, you won’t get good results.
Therefore, this it what I recommend you do:
This is an expensive hobby, so give your wallet a break.
If you’re keeping a fish only tank or a mix with soft corals, use Instant Ocean Reef Sea Salt Mix. If you’re keeping hard corals or your aquarium is stocked heavily, use Instant Ocean Reef Crystals Reef Salt.
These are inexpensive investments, and huge numbers of hobbyists swear by Instant Ocean.
You can try them out, and if you don’t like the results, move on to a more expensive brand.
Happy reefing!
Last update on 2023-12-01 / Commissions Earned / Images from Amazon Product Advertising API
