How to propagate gracilaria?


New member
I picked up about two cups of gracilaria at the lfs today and would like to propagate this myself as part of my tang's diet.

I have a 10g tank up and running with an empty AC150, two mini-jet powerheads, an airstone, 2" of dead sand, no live rock, and a single 15w GE Chroma 50 fluorescent bulb. I have also added 2 dividers made of eggcrate with all pump/powerhead intakes on the outside with the gracilaria in the middle.

Here's what it looks like so far:


Does this look like a workable setup for propagating gracilaria? Is this enough light?

I don't have a refugium on my main tank - could I use old water from the main tank to provide nutrients to the gracilaria? Anything else I'd need to add to get it to grow?

Also, I think I read that gracilaria doesn't go sexual like other macros. Is that true?

Thanks! :)
Can you take a close up pic of that gracilaria? I think it may be something else. If it's what I think it is, it is still good stuff and grows much like gracilaria. Your set up is workable, but I would add more light, on more 15w over that 10g should do the trick. The stuff (both gracilaria and what I'm thinking of) need lots of nutrients. I would actually add fertilizer and iron in fairly heavy doses for use in pure cultures like that. Set your flow up so that the algae slowly tumbles from top to bottom, this is how the algae farmers do it ;) As for going sexual, the stuff does sexual reproduce, but it doesn't do it in a destructive crash the tank matter like caulerpa does.
Thanks for your help! :)

For close-ups, this is about the best I can do with my cheapo digital camera:
Photo 1 (54k)
Photo 2 (89k)
Did my lfs mis-label this as gracilaria? I can tell you, for certain, that my purple tang mowed through some of this stuff like I've never seen!

For lighting, I could swap this lighting hood with one I have on another 10g Q-tank. The other one has two of those 19w 6500K 'spiral' screw-in PC bulbs. Would that work better?

As far as the tumbling motion is concerned - what's the best way to achieve that effect? Right now the two mini-jet PH's and AC150 are all pushing water from the top-rear of the tank toward the top-front. I'm beginning to think that the eggcrate might not be the best idea as the algae just gets sucked up against, it instead of tumbling around. Perhaps 2 or 3 Maxi-Jet 400's with sponges on the intakes would work better?

One more dumb question: I'm kind of on an 'algae kick' lately and I'm getting ready to place an order with so I can start culturing my own phyto. I'm ordering some "Micro Algae Grow" from them for the phyto culture. While I'm ordering from them, are the "Plant Fuel" products on this page something that I should consider for this macro tank?

Lastly, I assume an iron supplement from Kent, Seachem, etc. would work?

Thanks again - Cheers!
I don't know about the phyto but I have had good success growing gracilaria in my sump. I found that it did best with bright light and lots of movement. I personally don't think the tumbling motion is critical-I found it hard to maintain, but plenty of flow seemed important to avoid overgrowth of cyano. I also had a 250 watt MH over the 75 gal stock tank sump and the gracilaria grew like crazy. I would say add more light and make sure that you can notice the algae being blown around a bit by the currents and you should be fine. As far a adding nutrients I would be guessing as my experience was with growing in the sump. I suspect that as billsreef said, if you want to maximize growth it would be a good idea to add fertilizer, some iron and maybe manganese (often comes together with iron in additives for algae growth).
Hi gcvt,
I'm a big fan of f/2 (MICRO ALGAE GROWâ„¢, GUILLARD f/2 FORMULATION) but I don't know what to say about those other things. I suspect that the only thing you will need to add is iron. A suggestion on culturing phytolankton: early on before you go putting your homegrown phyto in your tank put it in the fridge for a couple days and let it settle to the bottom and take some of the clear water off the surface and perform a phosphate test. A common problem with homegrown phyto is that excess phosphates can be added to the display tank. I would recommend that you perform this experiment and figure out how long it takes the phyto to consume all the phosphates in the f/2. I believe that under 2 40w lights 1mL of DTs consumes 1.5mL of f/2 in 7 days.

Good luck!
Here is my Red Gracilaria farm tank.

29 gal tank, two Maxi-Jet 1200s power 4 spray bars that create a rolling water flow.

Two 65 watt power compacts provide light. Lighting is on 24/7.

I lined the egg crate with screening to keep the stuff from getting stuck in the egg crate.

The 25 fish in my 90 gal display tank (Nitrates undetectable, salifert) provide most of the nutrients, but I also add some Iron. I also have a second 29 gal refugium full of green macroalgae.

After one week, the gracilaria has doubled in size ( I weighed it before I put it in and once again after one week).

For a pic of the farm tank go here:

That's really spiffy. Mind if I ask you a couple questions? What kind of screen did you use on the eggcrate? How did you attach it to the eggcrate? Could you post more pics of the plumbing for the farm tank? Do you think the same rolling water flow would work well for chateomorpha?

How is your gracilaria (sp?) doing?

I used plain old nylon window screen from the local hardware store. I used plastic zip ties to secure the screen to the eggcrate. The eggcrate dividers are easily removed for cleaning, as is everything else (none of the PVC is glued). The pluming is nothing special. Powerheads feed into a tee intersection of Ã"šÃ‚½ inch PVC pipe. One powerhead powers two spray bars. My gracilaria farm tank is gravity fed from the display tank. Water leaves the farm tank (the tank has one whole drilled for the outflow) via a modified durso standpipe overflow (its silent).

I suppose the design would work for spaghetti algae, Iââ"šÂ¬Ã¢"žÂ¢ve never tried it. My spaghetti macro does quite well in my green macro algae refugium, which is also connected to the display tank. Water movement is achieved via 3 mini powerheads. The spaghetti competes just fine with several caulerpa species in the refugium.

Hereââ"šÂ¬Ã¢"žÂ¢s a pic of my spaghetti macro (looks like a tornado, must be time to harvest):
kmk2307 said:
How is your gracilaria (sp?) doing?

It's going okay so far. I thought I'd get more growth by now, but I ordered some plant 'food' from Florida Aqua Farms - hopefully that will help. Thanks for asking :)


I purchased 1 pound of gracilaria from a Florida farmer for my sump. I placed 1/2 of it in the refugium (slow water movement) and the oher half in the sump fast flow area. It appears to be doing fine in both areas for 3 weeks now. My system provides the high nutients needed ... have many fish and inverts... but also plenty of biological - live rock, mangroves, caulerpas and excellent lighting. The sump with the refugium has 2, 24 hr. -100 watt plant growth bulbs... if that helps in stimulating growth. the gracilaria is not being moved around much at all ...although it is in very shallow water bed above the dsb plenum and each ball getting plenty of light. I have had no problems with it yet. I take out just a small amount each day and feed my Sohal and Purple Tangs. I will keep you posted as to growth rate. I also add 1 capful (small amount) of Kent Marine Essential Elements (iodine, magnesium, calcium, iron) maybe thats why it's still alive or all of the items factor in. Many people have said that they had difficulties keeping gracilaria alive for more than a few days. IMO , gracilaria requires a very natural env. with plenty of nutrients. So FO anf REEF only tanks may not be suitable for this application. My system is somewhere in between.
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