Congratulations to community member SaltyBuddha and his 20 gallon nano reef for being selected for our June 2020 Reef Profile! This unique nano reef aquarium is dedicated to growing ornamental macroalgae, an often overlooked member of ocean ecosystems. In this article SaltyBuddha shares his experiences in the hobby and this aquarium's journey over the past year and a half. Please share your comments and questions in the comments section below, and be sure to follow his aquarium journal for additional photos, history, and information about this beautiful nano reef tank.
SaltyBuddha's 20g Macroalgae Nano Reef
Display: Aqueon 20g High - 16.5 gallon volume
Rock: Florida Reef Rock from Reef Cleaners
Sand: CaribSea Ocean Direct Live Sand Oolite
Lighting: (2) Kingbo 18W 6500k PAR38 Bulbs & (1) Kingbo 18W Reef PAR38 Bulb (Previously Current USA 24” IC LED)
Heater: Eheim Jager 75W Heater
Circulation: 1K Icecap Gyre, 1 Current USA eFlux Powerhead
Filtration: Aqua Clear 50 Power Filter
Filter Media: None
Top Off: AutoAqua Smart ATO Micro
Dosing: Kamoer X1 (Alk/Ca/Mg/PO4) & Jebao DP-4 (ChaetoGro/Microbacter7)
Established September 2018
The hardest part about this tank is maintaining a balance of nutrients between the macroalgae and coral. Initially, I would do a 25% weekly water change but that eventually proved to be too much. Now I perform a 10% water change every 3 to 4 weeks while adjusting the dosing regimen every week.
Macroalgae use bicarbonate in saltwater (compared to CO2 in freshwater) and certain macroalgae use much more than others. In my experience, Caulerpa Mexicana consumes more bicarbonate/nutrients than any other macroalgae.
I’ve found that I need to dose both NO3 and PO4 to keep both the macroalgae and coral happy. At one point my tank was consuming over 0.16ppm of PO4 per day.
It is also possible to control the caulerpa growth by reducing or increasing the available micronutrients. I often adjust the ChaetoGro dosage depending on how much growth I want.
- ESV Alkalinity/Calcium/Magnesium (Daily)
- Microbacter7 (Daily)
- ChaetoGro (Daily)
- Phosphate - Green Leaf Aquarium KH2PO4 dry fertilizer (Daily)
- Nitrate - Green Leaf Aquarium KNO3 dry fertilizer (Weekly or as needed)
- Ferrion (Weekly)
I’m currently switching to feeding mainly live & frozen food. These foods have a better balance of nitrates & phosphates that make it much easier to keep these nutrients at acceptable levels for both macroalgae & coral.
- Algaebarn OceanMagik Phytoplankton (45ml per day - recommended starting dosage is 5ml per 20g)
- NLS 1mm Algae Pellets & 0.5mm pellets (Daily)
- Ocean Nutrition Prime & Algae Flakes (Daily)
2-3x per Week
- Reef Nutrition Mysis Shrimp
- Reef Nutrition Oyster Feast
- Rods Food Seaweed Blend
- Coral Frenzy
- Reef Roids
- Seachem Zooplankton
- Brightwell Reef Snow
Alkalinity, calcium, nitrate and phosphate need to be adjusted weekly because consumption changes as the macroalgae grow out. This is especially true after I do any large removals of macroalgae because the consumption drops significantly.
The main parameters I try to maintain are:
- Alkalinity - 8.3 dKh
- Calcium - 420 ppm
- Magnesium – 1350 ppm
- Nitrate - 5 to 15 ppm
- Phosphate - .1 to .2 ppm (You might think this is too much, but at one point the tank was consuming .16ppm of PO4 per day!)
- Black Storm Clownfish (Amphiprion ocellaris var.)
- Starry Blenny (Salarias ramosus)
Soft & LPS Coral
- Green Sinularia Leather (Sinularia sp.)
- Purple Kenya Tree (Litophyton sp.)
- Various Zoanthids/Palythoas
- Duncan (Duncanopsammia axifuga)
- Purple Brush Gorgonian (Muriceopsis flavida)
- Purple Ribbon Gorgonian (Pterogorgia anceps)
- Purple Frilly Gorgonian (Pseudopterogorgia elisabethae)
- Tan Candelabra Gorgonian (Eunicea)
- Golden Plume Gorgonian (Pseudopterogorgia bipinnata)
- Decorator Crab (Pelia sp.)
- Blue Porcelain Crab (Petrolisthes galathinus)
- Various Hermit Crabs
- Two assorted Conchs
My favorite invert by far is the decorator crab. This came in as a hitchhiker on some algae and was smaller than a dime. Eight months later it is bigger than a half dollar. The one issue is that it likes to chop off Zoanthids for decoration.
- Caulerpa Mexicana
- Caulerpa prolifera
- Codium (both short & tall)
- Green Gracilaria
- Red Gracilaria
- Flat Branch Gracilaria
- Red Grape Botryocladia
- Fire fern
- Gracilaria Hayi
- Various Halimeda
- Mermaids Fan
- Pencil Cap
- Shaving Brush
I’ve lost plenty of macroalgae in this tank from various issues/crashes, but this is the current list. I’ve only had two instances of caulerpa going sexual and they were very small portions with zero side effects. Some macroalgae are much more sensitive than others. I’ve learned to separate any new macroalgae into a few different portions to place in varying flow/light conditions throughout the tank. This often insures at least one piece survives.
My favorite green macroalgae is Caulerpa Prolifera. It is gorgeous and very easy to maintain. For red it is either Gracilaria Hayi or Red Grape Botryocladia.
This 20 gallon started as a simple freshwater tank with some neon tetras and my crown tail Betta, Ben. After setting up a semi-successful mixed reef IM10, I decided to turn this into a macro algae dominated aquarium. I moved Ben out of his mansion and started researching macro tanks.
There are plenty of macroalgae tanks out there, but I could not find a lot of information on a macro dominated reef tank. I decided to order a bunch of macroalgae and figured the tank would run on its own.
My plan was simple: throw in a bunch of macros and let them filter out all the nutrients; leaving me with zero work. It sounded easy, but I eventually realized a macro dominated reef tank requires more finesse than I originally thought. The tank showed great growth and progress over the first half a year, but the tank would not sustain certain types of macros. Calcified macros and more sensitive species, like Blue Hypnea Pannosa, did not thrive and eventually melted away. I’d later learn that this was due to the low alkalinity and low level of available nutrients.
After almost two years I’ve realized the most important thing for this tank is maintaining NO3 & PO4 higher than you would usually see in a reef tank. It is very easy to keep this tank running at undetectable levels of phosphate and nitrate. Undetectable nutrients means the tank is right on the edge of coral sustainment and it eventually lead to a dinoflagellates outbreak. I fully believe that many of the tanks issues would not have appeared if I focused more on keeping the nutrients above 0.
I often let the tank grow wild for a month or two at a time and I think the tank looks best at these points. The macro algae often grow entangled into the coral but they don’t seem to mind. The tank almost always grows back differently after a large trim so it’s great to it reach a new equilibrium.
Troubles Along The Way
This tank has gone through two major disasters. The first was crash from a combination of Chemi-Clean & Kalkwasser about one year into the tank’s life. The tank did not adjust well to Kalkwasser and I had a large influx of issues that included cyanobacteria. I’d used Chemi-Clean successfully in other tanks, but something went really wrong. I lost all of my fish (filefish, Bangaii cardinals, & green banded gobies), Christmas tree worm, all of my LPS coral except the Duncan, 2 gorgonians & about a quarter of my macros. I’m still unsure why the Chemi-Clean reacted this way.
The second disaster is a dinoflagellates outbreak that I am still fighting. I confirmed that I have ostreopsis about 6 months ago. This fight has had a lot of ups and downs, but here are the main things I’ve found to be effective against dinoflagellates:
- Increasing NO3 to 10-15ppm and PO4 to at least 0.15ppm
- Adding live phytoplankton everyday
- Introducing pods and other forms of diversity
- Filter floss changes every day in the morning
Dinoflagellates still makes a strong recurrence occasionally, and I will eventually add a UV sterilizer if I can’t get it fully under control.
I have just two regrets with this tank. The first is not dosing two-part sooner. I did not test alkalinity until the tank was 8 months old. I assumed with only a small number of LPS and zero SPS that the weekly water changes would be sufficient to maintain alkalinity and calcium. When I first tested the tank the alkalinity was almost 5 dKh (water change water was at 11 dKh). The second regret is adding Caulerpa Mexicana to the tank. This species of Caulerpa imbeds its roots into the live rock at least 1/8” deep and makes it close to impossible to remove completely. This species uses the most bicarbonate & nutrients in the tank; making it difficult to maintain stability.
Brad908’s 40 gallon coastal biotope was a huge inspiration and made me want to make a macro dominated reef tank.
I am currently cycling a new 20g long tank that I will transfer all the coral/macros into. The mangroves are already in the new tank. The one macroalgae I will not be moving over is Caulerpa Mexicana because it strips the tank of nutrients and is impossible to remove. I’m confident that I can create a more successful nano macroalgae dominated reef tank (that is a mouthful) with everything I’ve learned. Eventually I would like to have a larger tank filled with gorgonians, sponges, colorful invertebrates and a wide range of macro algae. I’ve also always played around with the idea of a large display refugium connected to a mixed reef tank.