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Salt Mix Impressions

By Steven Pro

It is with some trepidation that I wade into the murky waters of the sea salt debate.  There are only a few other topics in ornamental marine aquarium keeping that elicit such a visceral reaction from hobbyists as arguments regarding the water that we use.  Brand “A” versus brand “B”, natural versus synthetic, and the raging disputes regarding the various experiments and publications regarding sea salts are a hot topic right now.  The only other discussions that become more heated are the substrate and lighting debates.  I am going to try to steer clear of the controversy and simply state my experience and impressions of the various brands I have used over the years.  For those of you interested in some of the ongoing deliberations, please see my list of related links at the end of this article.

Most retailers that deal in marine ornamentals stock a variety of salt mix choices in a variety of sizes.  Pictured here are buckets that make 160 gallons of Instant Ocean and Reef Crystals or 200 gallons of Crystal Sea.  Photo by Adam Cesnales

I will begin with the characteristics I consider when evaluating a sea salt.  I much prefer a solid alkalinity level and chose salts that have a moderate to high alkalinity levels, even if that comes at the expense of calcium concentration.  To me, it matters little if my calcium level is constantly 350, 400, or 450 ppm.  The growth rate of my animals seems to be the same regardless.  But, when the pH or alkalinity starts to dip, I see some adverse reactions.  These considerations strongly influence my preference in salt brands.

Aquarium Systems Instant Ocean and Reef Crystals are very popular and widely available.  Photo By Adam Cesnales

Aquarium Systems Instant Ocean

This salt has been around for decades.  It is tried and true and is quite possibly the most popular brand of artificial sea salt in the world making it easy to find at just about any local fish store that deals in marine ornamentals.  It is also a good value, being reasonably priced most places I have seen it offered for sale.  It is a little weak in both calcium and alkalinity levels, particularly when mixed with deionized water, but both can be adjusted relatively easy for little additional cost.

Aquarium Systems Reef Crystals

This is currently my preferred brand and has been so over the years.  While I have tried others over the years, I keep coming back home to Reef Crystals.  It is easily found, has an attractive price and I have never had any problems that I could directly attribute to it.  It also mixes to reasonable concentrations of calcium and alkalinity.

Aquacraft Bio-Sea

I just recently had the opportunity to try some of this salt and I have to say I was impressed.  I liked it just as much as any other brand of salt I currently use.  This salt also has the distinction of being one of the brands that tested very well in Dr. Shimek’s urchin larvae study, which is a strong plus to me.  The downside is that this salt is very hard to find.  I can’t find it for sale anywhere around me, and I really can’t recall ever seeing it for sale at any fish store in my travels across the country.  As such, it makes it hard for me to recommend.

hW Marinemix

Back when I first started in the aquarium maintenance business and I was working for someone else, we had one customer that special-ordered in this salt for us to use on his display.  It was a standard 55 gallon aquarium with an undergravel filter, driven by two powerhead water pumps and a canister filter.  There was no protein skimmer and very little live rock.  The majority of the decorations were bleached  coral skeletons.  This was truly back in the “olden days” of marine ornamentals when things generally did not go very well.  But, this tank was the exception to the rule.  It housed an Emperor Angelfish (Pomacanthus imperator), a pair of Maroon Clownfish (Premnas biaculatus) with a Bubble Tip anemone host (Entamacea quadricolor), a Yellow Tang (Zebrasoma flavescens) and an Algae Blenny (Salarias fasciatus).  Maintenance consisted of a monthly 75% water change, and every three months or so the canister filter was cleaned and media replaced.  I would describe the diet as adequate for the times.  As I recall, it was a variety of flake, freeze-dried, and frozen foods, but nothing like the quality that we take for granted today.  Lighting consisted of two normal-output, 40 watt fluorescent tubes, one Vita Light and one Blue Moon.

The surprising thing about this display was the health and appearance of the livestock.  Back then, keeping marine fishes was a tricky proposition.  But these fish not only survived, they thrived and demonstrated noticeable growth over the years.  And even more importantly, they were as beautiful as the day they arrived at the store for sale.  There was absolutely no fading of color or Marine Head and Lateral Line Erosion ( so common at the times.  Also, since I was working aquarium maintenance and we were servicing quite a number of other marine aquariums, I had a direct comparison to other similar setups with the same maintenance, livestock, and feedings and yet none was even close to housing animals of the same health and vigor.  Not to mention, this aquarium had a healthy anemone, an occurrence practically unheard of at the time.

The only thing stopping me from giving this brand a ringing endorsement is it has been over a decade since I have last used it.  The store I worked for never picked up the brand despite the endorsement of my manager, because the store’s normal distributors didn’t carry it, and none of my current vendors carry it either.  It is a sad fact of business that it doesn’t matter how good a product is, if you can’t get it, you can’t get it.  And, if no one in an area offers it for sale then the general buying public doesn’t demand it because they are unfamiliar with it.  If customers are not demanding a product, then the retailer doesn’t go out of its way to obtain it.  It is a vicious cycle. Without having more recent experience with this salt, I can’t offer a true evaluation, but I can say that if it became available again, I would certainly try it.

Marine Enterprises International Crystal Sea

This salt became very popular on the various online message boards shortly after Dr. Shimek’s sea salt bioassay testing and subsequent article (  I, like many others, experienced widespread bleaching problems when I used this salt.  I don’t know why my corals bleached the day after a water change with this brand of salt and frankly I don’t care.  I simply choose to not use this brand anymore in favor of other brands that don’t seem to cause such an unusual reaction.

Sea Chem makes two formulations of salt mix.  Pictured is the ReefSalt formulation which contains elevated calcium and alkalinity.  Photo by Adam Cesnales


I tried this salt a few years ago when it first came out and became all the rage amongst message board contributors.  The hot selling point for this brand is its high calcium level.  But that level comes at the price of low alkalinity, at least in the packages I used and tested.  And while I don’t mind making minor adjustments to bring levels up, the imbalanced ratio of calcium to alkalinity were particularly problematic for me to compensate for.

Seachem Reef Salt

I have only tried a few bags of this salt, but what I have seen I have liked.  The values seem reasonable and my system’s inhabitants didn’t seem to have any adverse reaction to its use.  I just have not used enough of it to give it a ringing endorsement as of this moment.

Tropic Marin Pro Reef

I just recently tried this salt and I have to say I was not impressed.  In every tank that I used this salt and with every package I tried, I seemed to experience an abundance of diatoms and film algae.  So while the pH, calcium, and alkalinity values I measured were all good and I didn’t detect any noticeable nitrates or phosphates in my batches, I still got excessive growth of algae on the glass necessitating more frequent cleanings.

Tropic Marin salt is yet another brand that offers a reef formula and general marine formula.  Photo by Adam Cesnales


My personal favorite right now is Aquarium Systems Reef Crystals.  As I said before, I have tried a variety of other brands and keep coming back to Reef Crystals based on my positive experience, widespread availability, and reasonable price.  I would also recommend Aquacraft Bio-Sea if you can find it.  I have also been intrigued enough with hW Marinemix and Seachem Reef Salt to continue experimenting with them.

Tips for getting the most from your salt mix

Always add the salt mix to the water, not the other way around.  Adding water to the salt mix briefly creates a very highly concentrated solution which can lead to precipitation of some ingredients.

Always allow newly mixed salt water to circulate with a powerhead or airstone at least over night before use.  This allows carbon dioxide to equilibrate with the atmosphere which normalizes pH.  It also allows oxygen to be added.

Check at least the alkalinity and pH of your newly mixed salt water at least once for each new package of mix that you open.  More than one manufacturer has released bad batches of salt in the last couple of years and an occasional spot-check might help reveal a problem and save the lives of your charges.  Not to mention that many commercial blends of salt are formulated for "average" tap water hardness and may need adjusted when used with demineralized/purified water.

Related Reading: 

Harker, Richard. 2003. “Is It Really in the Water, Part 1?” Advanced Aquarist Online Magazine, December 2003.

Harker, Richard. 2004. “Is It Really in the Water, Part 2?” Advanced Aquarist Online Magazine, January 2004.

Holmes-Farley, Randy. 2004. “Reef Aquarium Water Parameters.” Reefkeeping Online Magazine, May 2005.

Hovanec, Dr. Timothy & Jennifer Coshland. 2004 “A Chemical Analysis of Select Trace Elements in Synthetic Sea Salts and Natural Seawater.” Advanced Aquarist Online Magazine, September 2004.

Hovanec, Dr. Timothy, Elena Toy, Jennifer Westerlund, & Jennifer Coshland. 2005. “The Toxicity of Synthetic Sea Salts and Natural Development of White Sea Urchin (Lytichinus pictus) Larvae.” Advanced Aquarist Online Magazine, March 2005.

Marulla, Matthew and Thomas O’Toole. 2005. “Inland Reef Aquaria Sea Salt Study, Part I.” Advanced Aquarist Online Magazine, November 2005.

Marulla, Matthew and Thomas O’Toole. 2005. “Inland Reef Aquaria Sea Salt Study, Part II.” Advanced Aquarist Online Magazine, December 2005.

Sekha, Habib. 2003. “Toxicity of Trace Elements: Truth or Myth?” Advanced Aquarist Online Magazine, May 2003.

Shimek, Dr. Ronald. 2002. “Its (In) The Water.” Reefkeeping Online Magazine, February 2002.

Shimek, Dr. Ronald. 2002. “It Is Still In The Water.” Reefkeeping Online Magazine, March 2002.

Shimek, Dr. Ronald. 2003. “The Toxicity of Some Freshly Mixed Artificial Sea Water.” Reefkeeping Online Magazine, March 2003.


Seawater on WWM

Related Articles: Synthetic or Natural Seawater, Makeup water and storage; Marine Salts; A quick comparison of a few available salt mixes by Steven Pro, Specific Gravity, Water Changes/ChangingpH, Alkalinity, Marine Alkalinity

Related FAQs: Seawater 1, Seawater 2, Seawater 3, Seawater 4, Seawater 5,  & FAQs on Mixing, Supplementing, Storing, Moving, Physical/Chemical Troubleshooting/Fixing... By Make/Manufacturer: Natural Seawater. Synthetics: Aquarium Systems (Instant Ocean, Reef Crystals), Aquacraft (Marine Environments, BioSea...), Central Garden (Oceanic), Kent Marine (SeaSalt), Red Sea (Red Sea Salt, Coral Pro Salt), SeaChem Marine (Marine Salt, Reef Salt), Energy Savers (Coralife), Tropic Marin, Other Brands... About Buying Pre-mixed Seawater, About  Synthetics Manufacturers Advertising Claims... Treating Tapwater For Marine Aquarium Use, Reverse Osmosis Filtration 


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