What follows is a partial excerpt from the July/August 2025 issue of CORAL Magazine…
There has been a surge in aquarium hobbyists interested in keeping macroalgae display tanks over the past few years. The interest is global at this point, fueled in part by social media groups and a number of passionate macroalgae keepers in the hobby. And while there is a plethora of resources online and in print about setting up and keeping saltwater aquariums, with most resources leaning heavily on coral-dominated reef tanks, there is scant information available on the topic of keeping a thriving macroalgae-dominant aquarium. Most aquarists who keep macroalgae (macros for short) have had to rely on dated resources or information shared by the relatively small number of macroalgae keepers (at least compared to coral keepers) in the hobby who are willing to share their know-how online.
However, as is the case with keeping any aquarium, there is no singular way to create and maintain a thriving macroalgae aquarium. Dennis (Tigahboy) chats with two other inspirational and experienced macroalgae aquarists in the genre to discover their husbandry methods and the thought process that drives their success.
Mosaic Macros: Charles owns Mosaic Macros, which currently offers more than 50 species of macroalgae for sale online, with many rare species. He is also a passionate hobbyist who has kept a thriving, impressive macroalgae display tank for the past five years.
The Macro Lady: Amanda Tamillo is the owner of The Macro Lady, who sells a huge variety of rare macroalgae and products online. She is also a long-time macroalgae keeper and is known around aquarium shows for the beautiful macroalgae she grows and displays in vases.
Tigahboy: I’m Dennis, a passionate macroalgae-focused aquarist who has set up numerous macroalgae display tanks over the years. I have contributed to and been featured in articles, podcasts, and YouTube channels for my macroalgae display tanks, and was even awarded Reef of the Month on Reef2Reef.
What got you into keeping macroalgae? How long have you been keeping macroalgae aquariums, and what do you currently keep?
Mosaic Macros: I’ve been keeping macroalgae for around seven or eight years now. I was initially drawn to macroalgae as I enjoyed the vegetative, naturalistic look of common macroalgae at the time, such as Caulerpa and Gracilaria species. Caulerpa ashmeadii, Caulerpa lentillifera, and Gracilaria hayi were the three species that originally introduced me to the hobby. Right now, my main display includes over 50 species, including, but not limited to species of Caulerpa, Gracilaria, Botryocladia, Laurencia, Sargassum, Dictyota, Gelidium, Halymenia, Halimeda, Neurymenia, Hypnea, Cymopolia, Euchema, Galaxaura, Dichotomaria, Coelarthrum, Acanthophora, Nemastoma, Codium, Portieria, Bryothamnion, Fauchea, Haliptilon, Scinaia, and many more.
The Macro Lady: I’ve always been attracted to the natural look of a reef tank with macroalgae in it. My first reef tank in 2000 included Halimeda and Mermaid’s Fan (Udotea flabellum). Currently, I’m up to 18 tanks, and endless varieties of macroalgae dominate every one. My main display is a 150-gallon (568-L) mixed reef tank featuring a vibrant collection of macroalgae alongside various small-polyp stony (SPS) corals, large-polyp stony (LPS) corals, soft corals, and anemones. I feel it’s a dynamic and visually striking example of a thriving, diverse ecosystem.
What does a typical macroalgae tank/set-up look like for you (e.g., tank, filtration, lighting, pumps, etc.)?
Mosaic Macros: The typical macroalgae setup, I’d say, is not overly complicated. I’ve kept macroalgae in nano tanks, large tanks, and bowls. I’ve also kept macroalgae in tanks with filtration and without filtration. I keep lower flow on my macroalgae tanks, as most macroalgae without a holdfast are prone to being blown around. I’ve found the best lights to be full spectrum, usually those geared towards freshwater planted aquaria. Actinic coral lights generally have the worst performance for macroalgae in terms of growth. Lights specifically made for macroalgae are the best, though.
The Macro Lady: The easier and lower maintenance, the better. My favorites are nano/pico macroalgae setups. So much life can be kept in less than 5 gallons (19 L) with very little effort. Macroalgae helps keep the nutrients balanced. A simple vase with a micro heater, sponge filter and light are all that’s needed to start. Adding in established live rock rubble along with the macroalgae prevents the dreaded cycling process. The primary difference between a coral-focused tank and a macroalgae-dedicated setup is the lighting. Most macroalgae thrive under full-spectrum lighting, which can be provided by certain adjustable reef lights or even high-quality freshwater planted tank fixtures.
Tigahboy: I don’t think keeping macroalgae tanks has to be as complicated as reef tanks in terms of equipment. Light, heater, wavemaker for flow, and basic filtration are about it, for me. The more you filter out, the less nutrients are available for the macros, so in some ways less is more. I rely mostly on the nutrient exporting properties of macroalgae as the major source of filtration, and then I supplement with biological filtration (usually a mix of live rock, sand, bio media in a basic filter), filter floss to polish the water, and carbon from time to time. This media can be in a simple hang-on-the-back filter or the filter chamber of an all-in-one aquarium.
What do your water parameters look like? What are the critical parameters/elements for you?
Mosaic Macros: For my main display, the water chemistry is as follows…
Get all the insights from the experts in the July/August 2025 issue of CORAL Magazine, AQUASCAPING WITH ALGAE! This issue starts arriving to CORAL subscribers and retailers in the U.S. around July 1st, 2025.
If you missed it, you can still start with this issue when you purchase our new QUICK START options; AQUASCAPING WITH ALGAE will be the issue we send up until early August, 2025.
Once available at our Minnesota warehouse, you’ll be able to order a print copy as a CORAL Magazine back issue from the Aquatic Media Press webstore. Once released on the platform, you’ll be able to read this issue instantly when you access the digital edition with any active CORAL Magazine Subscription!
