Macroalgae tank setup

[kolius]

I'm planning to start a macro-algae tank but am a complete beginner to saltwater aquariums. There's a lot of conflicting information out there, so I'm looking for advice on the best setup for my tank. I recently purchased some secondhand equipment and have a few options for my setup. I'd like to keep additional costs low and want to make the tank as low-tech and energy-efficient as possible. Ideally, I'd also prefer a smaller tank to minimize the costs of water changes and heating. But the overall goal is to have my algae thriving, of course!

My current setup:
30 gal tank
Fluval 307 canister filter
5 kg or dry rock
12 kg of dry quartz sand
Just started from scratch, 3-rd day of cycling, ghost feeding and adding some NITE-OUT II Starter Bacteria daily

I'm considering downsizing to a smaller tank and ditching the filter altogether.

Considering Downsizing:
20 gal tank
Comline DOC Skimmer
Wave maker Aqua medic EcoDrift
a live rock

Which setup do you think would be the best option?

Also, with a $100 budget, what would be the smartest investment? I’ve heard live rock is a great investment for tanks, but is it as important for algae as it is for fish?

Lastly, which light would be better for growing macro-algae: a budget full-spectrum light from Aliexpress or the Fluval SEA Marine Spectrum LED?

Thanks for any advice.

 

[vlangel]

I am biased toward live rock and even in a macroalgae system, I still think at least some live rock is beneficial.

The sizes of either tank will work so that is a matter of preference. Some footprints and dimensions are nicer to work with than others. A bigger footprint could mean more expense in the light fixture although there are lower light macroalgae, usually in the reds. A taller tank might need a better light to penetrate to the bottom, so another consideration. I don't have knowledge of the 2 lights you mentioned so can't give an opinion there.

I have a macroalgae/softie/LPS display. I have live rock, a deep sandbed, and a sump with more macroalgae. I have no other filtration, no socks, no skimmer, no algae scrubber.

My tank has cheato, codium, caulerpa cupressoides, ulva in green and gracilaria hayi and botrycladia in red. If you have any other questions I will do my best to answer them.

 

[kolius]

My tank has cheato, codium, caulerpa cupressoides

Thank you so much! Your tank looks absolutely amazing, and something similar is definitely my goal. I actually have a million questions!

Is cycling a tank with macroalgae inside a good idea? I’m currently cycling my tank with some Caulerpa Prolifera Algae. However, I’ve read advice recommending cycling without light or plants, only adding the macroalgae once the tank is established. What’s your take on this?

What is your fertilization regime? How often you do water changes? I started growing macroalgae in a small 10-liter tank with brine shrimp. I dosed basic NPK and micro fertilizers (from my freshwater tank) and saw good macroalgae growth in the first week. I’m wondering if I can continue using the same fertilizers in my larger saltwater tank. I’ve currently raised NO3 to 5 ppm. Should I add more macros, or is there a risk of triggering a brown algae outbreak?

I don't have knowledge of the 2 lights you mentioned so can't give an opinion there.

Basically, I’m deciding between a full-spectrum LED for freshwater tanks and a specialized marine LED with a blue light spectrum. Some people suggest a non-marine LED for growing macroalgae. What’s your opinion?

My algae started melting (see photos). I thinking how I can remedy that

 

[vlangel]

Thank you so much! Your tank looks absolutely amazing, and something similar is definitely my goal. I actually have a million questions!

Is cycling a tank with macroalgae inside a good idea? I’m currently cycling my tank with some Caulerpa Prolifera Algae. However, I’ve read advice recommending cycling without light or plants, only adding the macroalgae once the tank is established. What’s your take on this?

What is your fertilization regime? How often you do water changes? I started growing macroalgae in a small 10-liter tank with brine shrimp. I dosed basic NPK and micro fertilizers (from my freshwater tank) and saw good macroalgae growth in the first week. I’m wondering if I can continue using the same fertilizers in my larger saltwater tank. I’ve currently raised NO3 to 5 ppm. Should I add more macros, or is there a risk of triggering a brown algae outbreak?



Basically, I’m deciding between a full-spectrum LED for freshwater tanks and a specialized marine LED with a blue light spectrum. Some people suggest a non-marine LED for growing macroalgae. What’s your opinion?

My algae started melting (see photos). I thinking how I can remedy that

I have had the same live rock for 25 years and just keep moving it to my new tanks when I upgrade. That way my tanks are automatically cycled. So in your case I think I would cycle without lights and macros.

My tank is now 8 years old and has hit a good balance of input of nutrients, (from food and fish) and output of nutrients (from the macroalgae and coral) so I am down to a 5 gallon water change 2-3 Xs a year. However I used to do a 10-5% weekly for years.

As far as additives I used to dose iron, and occasionally flourish when I was doing water changes. I would think what you dosed would be ok too. Now all I dose is All for Reef.

Like I said before, I don't know very much about the different LED fixtures, I used to be a die hard t5 gal til I couldn't get 30" bulbs anymore. I was super intimidated to move to LED but after watching BRS videos I settled on ReefBreeder Photon V-24 and I will say that I love it. It's reasonably priced compared to the high end LEDs and it comes in a smaller size that might work better for your tank.

As far as your caulerpa melting, I am not sure. Maybe try dosing iron.

PS Thank you for the kind words about my tank. It's not everyone's cup of tea but I like the ease of care and the lushness. My 1st love is actually fish and the rest is to give them a natural looking habitat to live in.

 

[Tinnerito]

I'm planning to start a macro-algae tank but am a complete beginner to saltwater aquariums. There's a lot of conflicting information out there, so I'm looking for advice on the best setup for my tank. I recently purchased some secondhand equipment and have a few options for my setup. I'd like to keep additional costs low and want to make the tank as low-tech and energy-efficient as possible. Ideally, I'd also prefer a smaller tank to minimize the costs of water changes and heating. But the overall goal is to have my algae thriving, of course!

My current setup:
30 gal tank
Fluval 307 canister filter
5 kg or dry rock
12 kg of dry quartz sand
Just started from scratch, 3-rd day of cycling, ghost feeding and adding some NITE-OUT II Starter Bacteria daily

I'm considering downsizing to a smaller tank and ditching the filter altogether.

Considering Downsizing:
20 gal tank
Comline DOC Skimmer
Wave maker Aqua medic EcoDrift
a live rock

Which setup do you think would be the best option?

Also, with a $100 budget, what would be the smartest investment? I’ve heard live rock is a great investment for tanks, but is it as important for algae as it is for fish?

Lastly, which light would be better for growing macro-algae: a budget full-spectrum light from Aliexpress or the Fluval SEA Marine Spectrum LED?

Thanks for any advice.

If you're planning on growing only macroalgae, a white, red, and cyan spectrum light should do the trick or in other words a freshwater plant light does well. If you're keeping corals/anemones as well, then you should get a full spectrum.
I think live rock helps, but mostly in that it speeds up the development process(I may be wrong) but I've never bought live rock for any of my tanks and macroalgae grows just fine. The rock will just take longer to establish ecosystems of bacteria, algae, etc. In terms of your hardware and tank size, I don't really think it matters. I have some macro growing in a 15 ounce jar right now as what was an experiment but they seem to do fine.

 

[kolius]

If you're planning on growing only macroalgae, a white, red, and cyan spectrum light should do the trick or in other words a freshwater plant light does well. If you're keeping corals/anemones as well, then you should get a full spectrum.
I think live rock helps, but mostly in that it speeds up the development process(I may be wrong) but I've never bought live rock for any of my tanks and macroalgae grows just fine. The rock will just take longer to establish ecosystems of bacteria, algae, etc. In terms of your hardware and tank size, I don't really think it matters. I have some macro growing in a 15 ounce jar right now as what was an experiment but they seem to do fine.

Thanks for your reply! Very useful info! May I ask about your fertilization / water change regime? I tried growing macro algae in a nano tank, it went well for a week but turned into a brown-algae apocalypses the next week (macroalgae got covered by brown and started dying out) Curious how you avoid this in unicycled tanks?

 

[GARRIGA]

Macroalgae is the filter. Basic Under Gravel filter all that's needed. Don't need wave makers although HOB would be nice for easy maintenance of mechanical and chemical such as floss and GAC as well as providing additional flow. Can go reverse flow UG but not really necessary. Just don't use a powerhead and let it be air driven. Just because it's salt doesn't need to be complicated.

One other option is use that canister to drive the UG and periodically stir the bottom to loosen detritus and force it into the canister. Let it decompose naturally as that will feed the macro. Keep the HOB for floss and GAC thereby eliminating the need to open the canister assuming large coarse media used. Let nature do nature. KISS

This latter option what I'm going to be running on a 20H except effluent from canister goes into a HOB where floss and GAC will be easily accessible and I can run a Fuge/ATS since main display will be soft or hard corals. Likely former as I really want KISS and grandson will enjoy tank full of damsels and soft corals and I'll enjoy not dosing or worrying about pH which in my house an issue due to excess co2. UG will catch and decompose detritus minimizing my involvement.

 

[Tinnerito]

Thanks for your reply! Very useful info! May I ask about your fertilization / water change regime? I tried growing macro algae in a nano tank, it went well for a week but turned into a brown-algae apocalypses the next week (macroalgae got covered by brown and started dying out) Curious how you avoid this in unicycled tanks?

I've never had any major algae issues, but my water change regimen is very minimal, and macroalgae thrives in high nutrient environments, especially caulerpa spp. I do a 10-20 percent water change every few weeks. For fertilization I dose chaetogro once a week, since macro are demanding in minerals. chaetogro will include iron, magnesium, zinc, and the list goes on. When I first started macro, they began turning clear, being a sign of nutrient deficiency, so chaetogro really saved me. You may want to dose more according to how much macroalgae you have. (ex. I dose twice a week in my systems with dense amounts of macroalgae.) I do have pretty large cleanup crews per tank if that says anything about nuisance algae, like hermits and snails which will control it, but you typically want to add them before algae becomes a problem as they do not eliminate algae, but rather keeps it from spreading too much. I'm glad I could be of help for you.

 

[kolius]

Basic Under Gravel filter

Thanks for advice. Not familiar with UG filters, will look into this!

One other option is use that canister to drive the UG and periodically stir the bottom to loosen detritus and force it into the canister

I should be able to release detritus into the water by stirring up the substrate and allowing it to be drawn into the canister filter, even without the under-gravel filter. Is it really necessary or can I use just the Canister?

Just don't use a powerhead and let it be air driven

I thought Reefers often avoid air-driven filters because the air bubbles can cause splashing, which leads to salt creep. I used to keep my macroalgae with a basic air-sponge filter, but I also found the flow rate wasn’t strong enough for good circulation and had saltwater spills around the tank

 

[kolius]

When I first started macro, they began turning clear, being a sign of nutrient deficiency, so chaetogro really saved me

Thanks for advice! I suppose there's nutrient deficiency on this photo down here as well?

 

[GARRIGA]

Thanks for advice. Not familiar with UG filters, will look into this!


I should be able to release detritus into the water by stirring up the substrate and allowing it to be drawn into the canister filter, even without the under-gravel filter. Is it really necessary or can I use just the Canister?


I thought Reefers often avoid air-driven filters because the air bubbles can cause splashing, which leads to salt creep. I used to keep my macroalgae with a basic air-sponge filter, but I also found the flow rate wasn’t strong enough for good circulation and had saltwater spills around the tank

Yes you can stir detritus and have filtration grab it but I'm suggesting that to keep macroalgae one can simplify the problem by using an undergravel filter. It's old school but not very profitable therefore not likely found in LFS yet can be had on Amazon and plenty on the net to explain it.

When air driven the water rises up the column and spills out like any other return. It's not like just adding an air bubbler. No salt splashing or salt creep. Checkout @Paul B Tank Birthday, 47 + years thread so you can see how old school still works.

 

[Tinnerito]

Thanks for advice! I suppose there's nutrient deficiency on this photo down here as well?

Most likely. You want to get those minerals up.

 

[kolius]

Checkout @Paul B Tank Birthday, 47 + years thread so you can see how old school still works.

Thanks so much for your reply!

Re: old school—great to know! I’m really curious to learn more about the culture and history of reef keeping.

It’s fantastic that this forum provides an opportunity to engage with such experienced reef keepers!

 

[SantaMonica]

Might want live sand instead of quartz; will help with some minerals.

Also if needed to reduce salt spray from bubbles you can put a small bubble remover cover, with a hole in it, over the bubbles.

 

[kolius]

Might want live sand instead of quartz

I know it’s not ideal, but it’s much cheaper. I also chose dry rock instead of live rock for the same reasons. What are my chances of success with this setup? Is live sand similarly critical for a macroalgae tank as it is for fish/corals? I’m also dosing some starter bacteria daily. It's my 2nd week of cyclilng

 

[Subsea]

I know it’s not ideal, but it’s much cheaper. I also chose dry rock instead of live rock for the same reasons. What are my chances of success with this setup? Is live sand similarly critical for a macroalgae tank as it is for fish/corals? I’m also dosing some starter bacteria daily. It's my 2nd week of cyclilng

I already mentioned silicates from your quartz sand contributing to diatoms.

Get a good clean up crew: Everybody eats diatoms, including copepods & amphipods.

PS: Fast growing macro algae will consume 30 fold more nitrogen than phosphorus. I dose ammonia and concentrated liquid kelp.

 

[Subsea]

@kolius

I grow ornamental seaweed commercially for sale to LFS. Consider using a calcium reactor to grow your macro algae. Very similar to fresh water planted tanks that use carbon dioxide to encourage growth. When CO2 bubbles thru aragonite, carbohydrates & trace minerals are dissolved. In addition, alkalinity increases which is a pH stabilizer.

 

[Tinnerito]

I use dry rock and sand too. Money is a key factor to consider with aquariums! It will be a bigger challenge though that's for sure.

I know it’s not ideal, but it’s much cheaper. I also chose dry rock instead of live rock for the same reasons. What are my chances of success with this setup? Is live sand similarly critical for a macroalgae tank as it is for fish/corals? I’m also dosing some starter bacteria daily. It's my 2nd week of cyclilng

 

[kolius]

I grow ornamental seaweed commercially for sale to LFS

that’s fantastic! Could you share some of your experience? My red algae is mostly fine, but green algae isn’t looking good. Caulerpa prolifera seems to be melting, and Caulerpa cylindracea is even more affected—some bits are falling off, and I’ve had to remove them. From what you can see, does this look like an issue with nutrients, insufficient light, or maybe a calcium/alkalinity imbalance?

Also, is it okay to place these algae on rocks? I’ve read that Caulerpa prolifera and Caulerpa cylindracea should ideally be rooted in the sand, but it’s pretty dark down there in my setup. Would attaching them to rocks still be suitable?

 

[Subsea]

Caulerpa species are fast growers. I suspect your nutrients aren’t sufficient.

Understand this: (Macro algae). Seaweed growth is not controlled by the most numerous nutrient but it will be limited by the least numerous element. What that means is operate nutrient rich systems that don’t limit trace minerals. For that purpose I add concentrated liquid kelp and because Caulerpa consumes 30 fold more nitrogen than phosphorus, I add ammonia.

“Also, is it okay to place these algae on rocks? I’ve read that Caulerpa prolifera and Caulerpa cylindracea should ideally be rooted in the sand, but it’s pretty dark down there in my setup. Would attaching them to rocks still be suitable?”

@kolius
It’s your tank. Put them closer to the light. My guess is it will worsen the process of insufficient nutrients and seaweed going sexual as a survival technique. I think that the reason Caulerpa was discouraged from growing unto “premium”live rock was because of desirables being covered by seaweed. With dry rock, that not an issue, however, you will have difficulty removing holdfast if you wish to grow other stuff on the rock.

I don’t know your experience level or quality of test kits but 5ppm of nitrate is TOO LOW for sustained macro growth.