Macroalgae is a growing sector of the saltwater aquarium hobby, and one of the pioneers of that movement is Macroalgae Scaper @tigahboy.h2o with his numerous sublime saltwater scapes. We asked the man himself about his tanks, his background in the hobby, his advice, what his dream tank would be, and his five favorite species of macroalgae.
Did you always do macroalgae setups or did they come as an evolution from freshwater planted or coral tanks?
I’ve kept saltwater aquariums since 2004. I used to keep more traditional mixed-coral reef tanks with macroalgae only serving as additional filtration via a refugium. But in 2018 I started to add macroalgae as a decorative element in my coral tanks. From there I transitioned to setting up my first macroalgae-dominant display tank at the beginning of 2020 which happened to be featured by Reef Builders in this article here.
I fell in love with macroalgae and marine planted tanks, and I’ve been keeping macroalgae only tanks from that point on. Given how fast macroalgae grow, macroalgae display tanks reach their peak much faster than coral reef tanks – in a matter of months rather than years. Because of this, I usually keep the tanks running for maybe a year (some less and some more) before I take them down and start a new project. I’ve set up over a dozen macroalgae display tanks since my first one in 2020.
How many tanks are you running right now?
I’m at my leanest right now with just three macroalgae tanks: 1) an Ultum Nature Systems/UNS 90U (68g) which is plumbed to a 20g Fijicube sump which has been running for the past 9 months, 2) an Innovative Marine Nuvo Fusion Pro 30L (30g) which has been running for the past 2 years, and 3) an Oceanbox Designs MicroTank P-1G (1g) which has been running for almost a year.
Have you had any problems along the way?
I’ve had a lot of problems with dinoflagellates (Ostreopsis primarily), Bryopsis, and hair algae of various kinds in all of my tanks. I’ve been able to manage all of it with a lot of time and effort, but it definitely becomes a problem in macroalgae tanks where nutrients can easily bottom out if you don’t keep enough nutrients in your system, and with Bryopsis and hair algae often hitchhiking their way into tanks on other macroalgae and thriving with the added nutrients in a macroalgae tank.
Finding the right nutrient balance (not too little and not too much) and having a healthy diverse microbiome are my approaches to mitigating those issues, though of course a good amount of elbow grease to remove unwanted nuisance algae and dinoflagellates is critical as well.
What would be your advice to anyone who wants to set up an aquarium like yours?
Don’t over-filter the water since macroalgae actually need those nutrients to thrive and be ready to dose extra nutrients as needed. Also, be prepared to make regular and frequent trimming a part of your maintenance routine – both the macroalgae themselves and any unwanted hair algae or Bryopsis that may be growing on them.
Macroalgae (along with nuisance algae) grow really fast and if you let them get out of control, you’ll struggle to get things back under control and unwanted nuisance algae such as hair algae and bryopsis will find a happy home among the untrimmed/untamed macroalgae.
Finally, please appropriately dispose of macroalgae, especially Caulerpa species which can be very invasive. Be sure to not let macroalgae go down the drain and never dump directly into any waterways. The best practice when disposing of macroalgae is to use a filter sock to catch macroalgae when you do water changes and freeze any macroalgae for 24 hours before you discard it in the trash or compost.
What do you feed/fertilize your macroalgae with?
I still dose the same dosing regimen that I used for my very first macroalgae display tank back in 2020: Brightwell Aquatics ChaetoGro, NeoNitro, NeoPhos, and Ferrion. This dosing plan provides the major and minor elements/nutrients that macroalgae need to thrive, and I’ve had a lot of success with this dosing routine. I also have used different products along the way to dose Calcium, Alkalinity, and Magnesium, but currently, I’m dosing Tropic Marin All-For-Reef.
What spectrum/par lighting do you recommend for macroalgae?
Full spectrum lighting at around 6500K/6700K works well for most macroalgae, but macroalgae found deeper in the ocean may benefit from more blue spectrum. Freshwater planted tank lights work well since they are at around 6500K/6700K, but more recently I’ve been using reef lights that you can adjust to get close to the spectrum I like.
Most of my macroalgae tanks have had PAR at close to 400 towards the top of the tank and then closer to 100 or so at the bottom. But I’ve had plenty of tanks with PAR maxing out closer to 200 and the macroalgae in there were thriving as well. All that to say, most macroalgae can adapt to a wide variety of lighting so you don’t have to obsess about getting the exact spectrum or PAR.
Are there any macroalgae-eating fish or inverts that people should avoid?
I generally avoid tangs, angelfish, butterflyfish, and any other fish that would eat mostly nori/seaweed. Though most of my tanks are too small to keep those types of fish anyway. Most smaller snails (e.g. Astreas, Ceriths, Nerites, Margaritas, and Trochus) and hermits are fine to keep with macroalgae and I keep a decent variety of them in my macroalgae tanks. But I would avoid the larger Mexican Turbo snails, sea hares, sea urchins, emerald crabs, and larger hermit crabs who can do more damage to the macroalgae.
Do you notice a pH/CO2 swing at night, or doesn’t it matter?
There will definitely be swings with a drop in pH with lights off but I haven’t noticed any adverse effects to my tank inhabitants. For my UNS 90U which has a sump, I do run lights on reverse photoperiods to help minimize the pH swings.
What are your top five favorite macroalgae species?
This is the hardest question to answer because I love them all! But since I have to pick, I’ll go with a nice range of shapes, colors, and textures with the following 5:
1) Hypnea pannosa (beautiful blue macroalgae),
2) Neurymenia fraxinifolia (a deep red macroalgae that has a ribbon-like shape),
3) Codium sp. aka Dead Man’s Fingers (for a darker green color and thick cylindrical branches),
4) Caulerpa paspaloides which have palm-tree like fronds around a cluster of fronds,
5) Rhipocephalus phoenix aka Christmas Tree macroalgae which look like tiny little Christmas trees because who doesn’t like Christmas?
What’s your favorite fish to add to a macroalgae tank?
Currently, I’m obsessed with my Yellow Banded Possum Wrasse who is not only super cute but also loves cruising through macroalgae. He glides effortlessly in and out of macroalgae clumps which looks just super natural to me. I also really like keeping mollies in my macroalgae tanks because they come in so many beautiful colors and do a great job with picking diatoms and nuisance algae.
I started keeping mollies after watching a YouTube video by Reef Builders/Jake Adams on the topic of acclimating mollies to saltwater aquariums.
What tanks are you working on next?
I have a lot of projects in the works! I recently obtained a bunch of seagrass from Julian Sprung at his Two Little Fishies booth so I am working on setting up a small seagrass tank. I also recently got my hands on a couple of Ultum Nature System’s brand new UNS Dual All-In-One Tanks (a 7g and a 21g) which are both saltwater ready, and I plan to set up additional saltwater tanks with those (maybe even a coral tank!).
On top of all of that, I have a freshwater project in the works as well. I’ll be posting regular updates on my Instagram (@tigahboy.h2o) as well as FB (https://www.facebook.com/tigahboy.h20) and my Reef2Reef thread (https://www.reef2reef.com/threads/tigahboys-macroalgae-tank-s.737622/), so stayed tuned for a lot more!
What would be your dream tank?
My dream tank would be a shallow, peninsula-style display tank of around 100 gallons filled with a mixture of macroalgae, seagrasses, soft coral, and a large anemone. I’d like to have that connected to a large sump with a dedicated grow-out space for macroalgae frags.
*All images copyright @tigahboy.h2o
