The salty garden...

As more and more interest grows in the brackish water world of “Estuary”, we’re seeing more and more questions about putting together aquariums. Our community really gets the idea that a brackish water aquarium is as dynamaic, biologically rich, and aesthetically unique as any type of aquarium we play with. We see little fear of our vision of tinted, brackish water, epiphytic biofilms and algae on mangrove branches, mangrove leaf litter- and an abundance of life.

Beyond the initial questions of “What fishes can we keep”, and “Do I have to use a hydrometer or refractometer?” (quick answer: Yes. No guessing at specific gravity! ) the most common question is, “Can you grow plants in a brackish aquarium? Which ones?”


Of course, we have talked before, and will talk much more- about growing mangroves in our brackish-water systems. They're the definite "go-to" for brackish water systems, and display surprising adaptability and tenacity...oh, and they look cool, too!

And you kind of knew that already, huh?

Today, however, we’re just going to focus on two of my favorite favorite brackish water-tolerant aquatic plants. Now, the consensus for many years was that there aren’t too many plants that can adapt to brackish conditions. Although it is true that there are a limited number of plants which are found in these habitats which make it into the trade, there are also a few “old faves” that are surprisingly adaptable to the lower specific gravities (1.003-1.005) that we are targeting, like Bacopa, Hygrophila (specifically, H. corymbosa), Anacharis, Cabomba, Hornwort, and even some Sagittaria and Echinodorus (the “Pygmy Chain Sword”)…

Lots of possibilities.

I’ve played with all of these over the years in brackish environments, and they do work…if you acclimate them slowly. Oh, and a number of my friends tell me that Vallisneria works, too, although I must say I have NOT personally used them in a brackish tank before.

Vallisneria (Photo by Fredlyfish4, used under CC BY-SA 4.0)

Before we get into our extremely quick-and-dirty rundown, let me make a general suggestion: You need to gradually acclimate any plants that you’ll be keeping in your brackish tank to these conditions over the course of a week or two. You can’t just plunge plants (even ones that are known to be adaptable) from pure freshwater at the LFS right into your 1.005 brackish water aquarium and expect them to kick ass.

Acclimate them. They key is to keep them in a separate small aquarium during this time, and “dial up the salt” gradually (like adding some every other day and checking the impact on your specific gravity to bring it up by a point or two…I’d recommend a refractometer (even a digital refractometer, if you can afford one!) instead of a hydrometer, because it’s easier to resolve the smaller increments that you’ll want to track during this process, especially if your eyesight sucks, like mine does! Once your at your target specific gravity of 1.003-1.005, let the plants stay in the tank a couple more days in order to allow them fully acclimate. The key here, like in every aspect of aquarium keeping…is patience.

You can’t rush this; there is no reason to.


Also, as another generality, most of the plants that we consider for this habitat will benefit from nutrient-rich substrates, incorporating muds or even terrestrial soils- the exact kinds of substrates that we’re advocating for your brackish water aquarium! Think more "pond" or "dirted planted aquarium" than clean, white sand" kind of thing here. And of course, if you’re contemplating growing a live mangrove or two (or more) in your tank, the rich substrate is really important, IMHO. Part of our whole approach to brackish systems is that we need to replicate, to the extent possible, the entire habitat, specifically, the substrate.

Now, real anaerobic mud, as encountered in many intertidal mangrove estuaries and other habitats, is pretty impractical to incorporate in the aquarium, but we can do a pretty reasonable facsimile with the right materials, which will provide benefits beyond just giving your plants a place to grow (such as fostering microbial  life and macro crustaceans and other beneficial life forms which make up these systems). In future installments of "The Tint", we'll discuss "recipes"  and ideas for mud substrates in brackish tanks.


As you all probably know, I am absolutely not a plant expert, or even a huge planted aquarium lover.

I appreciate them for their utility, and admire the amazing aquascapes created by many of you talented people, but they never quite “grabbed me” like fish did. I mean, I am in love with blackwater habitats in which plants are a minor component, if present at all- can you blame me?

However, like so many things we do in the hobby, I learned what I needed to know to do what I do, and little more. However, I did spend a fair amount of time over the past decade trying to research and test which plants work in the low-salinity brackish environment we’re targeting, and I can offer a few suggestions solely based on my experience, and that of a few friends. This is a scant few; there are no doubt many others, but you might need to do some digging around online or elsewhere to get more information.


SInce I’m about not wasting your time, let’s just cut right to the plant that I feel is the “target specimen” for your tinted brackish system…a plant which is actually often found inhabiting brackish water habitats, right along side mangroves and Nypa Palms  Cryptocoryne ciliata. Native to Indonesia, India, and the Philippines, this is one of the larger Crypts, reaching up to 20 inches tall ( 50.8 cm) and will often “break the waterline” with it’s leaves…kind of perfect for some of the effects we’re after in our brackish tanks! When planted in a taller aquarium with a “thicket” of mangrove roots, this plant can form the basis of a stunning functional and aesthetic display that will really look alive! 



Like all “Crypts”, this one benefits from a rich substrate, so incorporating the aforementioned muds, clays, and soils into your aquarium makes perfect sense. And of course, like others in its genus, it often goes through that nasty “Cryptocoryne melt” as it settles into its new environment. The key, again, is patience. Let it happen. I’m no authority on dealing with planted aquarium problems, but I’m patient as ________, and, like you- I’ve found that providing the proper conditions and just waiting it out works the majority of the time with these plants.

Panicking, uprooting, moving them about, and creating general disruption typically provides no benefit for the plants, and will only give you some sort of mental comfort that you did “something” to your tank…If you’re patient, you’ll find that the roots tend to survive the “melt”, and new leaves may appear within a few days or weeks- or over the course of a few months sometimes.

(This is similar to what happens with seagrasses, just so you know. Remember that next year…) Seriously, there is no real need to panic..just wait it out. Let the rich substrate, decomposing mangrove leaf litter, and fish waste work their magic...

The other plant I implore you to consider would be the old standby, Java Fern! Yup, good ‘ol Microsorium pterous, which I think is Latin for “Even Fellman can’t kill this thing”- look it up!

It’s pretty much an indestructible plant, and as we have probably read forever, is easy to grow epiphytically, attached to mangrove roots or even well-placed rocks. The key to keeping this plant happy, in my opinion, is to place it in water. Seriously. That’s like about it…Okay, far be it from me to disrespect this old fave, but it really is absurdly adaptable to a wide range of conditions, and brackish happens to be one of them. 

Javas love aquariums with adequate “fertilizers”, in the form of fish waste and organics, so our version of a brackish aquarium, with decomposing leaves, botanicals, and muddy substrate- not to mention, a good number of fishes- is perfect for these guys! At the risk of re-hashing the details on a plant that is covered in like every aquarium website on planet earth, let’s just say that it’s adaptable, undemanding, and will do very well in brackish once adapted.


So yeah, we could go on an on and talk about each and every plant I’ve tried in brackish, and the notes would basically be the same…acclimate slowly, provide the proper “rooting environment”, lighting, and keep their leaf surfaces free of algae. If you’re really into CO2 or that other planted tank gadgetry, go for it, but quite honestly, I’ve never used a CO2 system in a brackish display, particularly our version of a “botanical-style/tinted” brackish tank, and my plants have historically grown really well once acclimated…



The idea of planted brackish tanks has been around as long as hobbyists have played with brackish tanks! It’s not something we’re inventing here. However, we are approaching it “institutionally” differently than most have before. That is, we’re embracing the idea of really rich substrate, mangrove leaf litter, and slightly tinted water.

This is, in our opinion, a more functional and uniquely alluring aesthetic than most have tried, and we think that this slightly unorthodox approach might yield some interesting discoveries as more and more hobbyists “dip their toes” in this fascinating aquatic niche.


(Okay, so a Spotted Scat is not the best choice for a planted tank...but it's a classic brackish water fish...)

And guess what?

Just like in our interpretation of the botanical-style, blackwater aquarium, which you have elevated, iterated, and evovled- YOU are an active participant in the evolution, discovery process, and development of this new tinted brackish-water aquarium movement, too.

Each and every hobbyist  who works with this type of system has the opportunity to contribute richly to the “state of the art” of this niche, and to the larger aquarium hobby. It’s an exciting “ground-floor” opportunity, and we’re happy to have you along for the ride!


There are so many things to learn. SO much to share, experience, screw up, and perfect.

Stay excited. Stay bold. Stay patent. Stay fearless!

And Stay Wet. (and slightly salty!)


Scott Fellman

Tannin Aquatics

Scott Fellman
Scott Fellman


5 Responses


September 26, 2020

What I truly live about brackish environments is it is kind of a no mans land. Things start to get too salty for plants and critters and not salty enough for a lot of marine life. So this gives us the decay we seek. Almost a graveyard look at first, but upon closer examination it’s full of small life. Benthic fish and reclusive crustacean and mollusks. The only disappointment for me is the lack of the high end brackish fish. Most fish in the hobby can only handle 1.005 and below. Those that can handle higher in the hobby are merely temporarily brackish. I have a 40 gallon long that has several thin striped hermit crabs and grass shrimp. I have been trying to “fight” the cloudy water. I now realize it’s not cloudy from the nitrogen cycle. It’s the constant busyness of the crabs keeping the sediment of the sand and crushed coral floating. I can handle some turbidity now that I know it’s not an ammonia problem.

Scott Fellman
Scott Fellman

September 26, 2020

Great observations and insights about a cherished wild habitat, Matt! The Chesapeake is fascinating in its own right! Brackish is such an interesting and engrossing world…we’ll be doing more with it in 2021!



September 26, 2020

Wonderful information. I recently had the opportunity to visit the Chesapeake Bay Area. I did some collecting in tidal creeks, a small inlet and the saltier end of the bay. The water was so dark you couldn’t see more than a few inches down. But when you got a cup, it was clear with a yellow tint. Fallen leaves from oaks and magnolias, piles of oyster shells, and debris from the shoreline grasses and marsh mallow littered the sand and black muddy bottom. I brought home dead oysters covered with barnacles, small anemone, mud crabs, macro algae’s, tunicates, grass shrimp , thin striped hermit crabs and a striped Blenny (Chasmodes bosquianus) and naked goby. The salinity was 1.012 at time of collection. After two months of my tank being up I upgraded the tank. It had a strong yellow tint to the water. When moving the hardscape I discovered (thanks to the mud crabs eating the barnacles ) a chunk of barnacles was actually growing on a peice of driftwood. The brackish world is definitely beyond sand and dead coral.

Scott Fellman
Scott Fellman

February 21, 2018

I can totally relate to your thinking on mangroves. And I think it’s largely a manner of expectation management. We had this same issue in reef tanks, where aquarists really wanted to be able to give them significant credit for “nutrient export” mechanisms, when the reality is that they do grow SOOO slowly as to barely impact this in a typical aquarium (I recall reading somewhere that you’d need like 100 actively-growing mangrove seedlings to affect any meaningful nutrient export on a 75 gallon tank- not sure how the calculation was arrived at, but..). Other than public aquariums, there are few examples of true full sized “trees” in aquariums. I have seen many 3-4 foot, years-old mangrove trees in home aquariums…That being said, it’s unusual to see them, because of our (collectively) impatience with slow-growing stuff in aquariums! That’s why I Like the combination of roots and perhaps some propagules for that added “touch”- but patience is the real key…ANd utilizing other salt-tolerant plants is the best way for many hobbyists to experience the “green” side of a brackish water aquarium, IMHO!



February 20, 2018

Perfect timing for this topic for me, I’ve just made an order for brackish-tolerant plants for my upcoming estuary-themed tank – java fern, java moss, moneywort, anubias and vallisneria. This will hopefully work as a nice, well-rounded set of plants that fit the various roles needed for filtration in planted aquaria. Since I’m using wood hardscape as roots I was thinking about mounting the anubias on top to simulate the mangrove leaves.

I don’t know how I feel about mangroves in aquaria. They are nice in theory, but the end result is a bit like keeping a goldfish in a bowl – it kinda works, but you need to do lots of maintenance on it and end up with a stunted version of what it could be in a larger enclosure. A mangrove bonsai, on the other hand… Perhaps the growth is simply too slow and we haven’t seen any examples of long-term mangrove setups, but most of the ones that I’ve seen look like a few sad little sticks. I’d be interested in knowing if anyone has had a tank where the mangroves grew large enough to develop either knee, stilt or pencil roots.

Leave a comment