Any experience with sargassum?

[BeachWater2]

A few weeks ago I accidentally brought home a sargassum crab Portunus sayi, with some water from the beach. I had one before, so I knew he needed his own tank. They eat everything. He's in a bucket for now, with a little HOB filter. I got him some sargassum, which slowly died, and he ate it. I just gave him some fresh. He wasn't being photogenic. He swims around a lot.

I've tried growing sargassum in my 16 gallon a couple times, and managed to keep some alive for a couple weeks, but no longer. The stuff we have at the beach is pelagic Sargassum (natans, fluitans). This time I tried collecting a bunch of different samples, and broke all the dark brown stuff off, keeping only the tips. My thought is that with a variety of different samples, some might live. Pickings weren't the best this time. I got it tumbling in the bucket, because when it stays above water it dies. I think that will help. You can see some dying "leaves" from being stuck above water. It's in fresh natural seawater, 0 nitrates, 0 phosphate, etc. I have some nitrate, iron, and Chaeto Grow I can try adding.

Lighting is only an LED daylight light bulb, but I just put an inexpensive purple grow light on it. The little guy might think it's a bit too groovy. I'll work on that. This is low budget.

I would really like to get this growing.

Thanks!

 

[Jay Hemdal]

I've never been able to keep the pelagic Sargassum natans alive, even under metal halides. I've seen other species of Sargassum growing off rocks, those might do better, but collecting algae attached to rock is illegal in most areas.

Jay

 

[taricha]

I've never been able to keep the pelagic Sargassum natans alive, even under metal halides.

That's pretty wild. I just assumed the difficulty with sargassum was insufficient light to simulate direct full sun.
Humbling to think about the things we can't figure out how to grow in this hobby.

 

[WheatToast]

I grew Sargassum muticum quite well with upper-moderate flow (Two Jebao RW-4’s pulsing on the highest strength on either side of the tank), high lighting on the Finnex Planted + 24/7 (lots of white and a bit of red and blue, forgot the specifics), and not much else. There were no fish in the aquarium, nor was I dosing trace elements, so the algae was probably getting by on the nutrients and trace elements present from the aquarium’s cycle (it was a few months old and the skimmer was rarely on). It doubled in size in around 2 months before I put it in the shade, cut it into smaller individuals, and introduced large amounts of competing macroalgae, killing it .

 

[WheatToast]

Here’s an image from January 2020:

Here’s an image from February 2020:

I should also note that the system I kept it in was a temperate (68 degrees Fahrenheit) 40 breeder with a HOB filter.

 

[BeachWater2]

I grew Sargassum muticum quite well with upper-moderate flow (Two Jebao RW-4’s pulsing on the highest strength on either side of the tank), high lighting on the Finnex Planted + 24/7 (lots of white and a bit of red and blue, forgot the specifics), and not much else. There were no fish in the aquarium, nor was I dosing trace elements, so the algae was probably getting by on the nutrients and trace elements present from the aquarium’s cycle (it was a few months old and the skimmer was rarely on). It doubled in size in around 2 months before I put it in the shade, cut it into smaller individuals, and introduced large amounts of competing macroalgae, killing it .

Thanks guys.

Wow. I like the shells. What trace elements? I did a lot of googling, and my theory is that the problem is nutrients. It might be phosphorus. I ordered some trisodium phosphate. I'll check back as I learn more.

I also grow seagrass, Turtle Grass - Thessalia testudinum. It was kind of fiddly to get started, and it's not exactly going bonkers, but it is growing and the roots are developing. We also get Manatee Grass - Syringodium Filiforme, but I haven't been able to find any good samples to plant. The area just off the beach is kind of a desert.

 

[DrZoidburg]

I had good success with this plant a while back. Keeping normal parameters. Initially every thing died. Tank had t5's and fuge had led's. Randomly popped up in both areas. Don't be surprised if it dies off then randomly appears on rocks or sand someday.

 

[WheatToast]

What trace elements? I did a lot of googling, and my theory is that the problem is nutrients.

Basically the stuff that is in this: Chaeto GRO

I would agree with you that a lack of macronutrients (ex. nitrates and phosphates) was a big contributing factor in the death of your Sargassum (mine as well as a result of competition from other algae and a lack of macronutrient sources). However, I also believe a severe lack of (pulsing) flow is killing the Sargassum (the only source of flow in that bucket appears to be the HOB filter). Mine did well under ~50x turnover per hour.

I also grow seagrass, Turtle Grass - Thessalia testudinum. It was kind of fiddly to get started, and it's not exactly going bonkers, but it is growing and the roots are developing. We also get Manatee Grass - Syringodium Filiforme, but I haven't been able to find any good samples to plant. The area just off the beach is kind of a desert.

Nice! I am planning on growing seagrasses as well! Do you have any tips for growing Turtle grass? Also, if you cannot find any Manatee Grass, you could try this site: Aquaticus Plants

 

[DrZoidburg]

I would agree to that big contributing factor is other algae out competing cause they are sort of a slow grower.

 

[BeachWater2]

Basically the stuff that is in this: Chaeto GRO

I would agree with you that a lack of macronutrients (ex. nitrates and phosphates) was a big contributing factor in the death of your Sargassum (mine as well as a result of competition from other algae and a lack of macronutrient sources). However, I also believe a severe lack of (pulsing) flow is killing the Sargassum (the only source of flow in that bucket appears to be the HOB filter). Mine did well under ~50x turnover per hour.


Nice! I am planning on growing seagrasses as well! Do you have any tips for growing Turtle grass? Also, if you cannot find any Manatee Grass, you could try this site: Aquaticus Plants

Thanks. I don't know what experience you have. It's easy, you just have to have some patience for it to get started. Some will die and their roots start rotting, so keep an eye on it. Freshwater people say that plants often die off when replanted. Turtle grass grows on thick runners/roots, all in a row. I get it from the beach wash. Try to find the ones that have smaller roots radiating off the big root (not just tiny hairs). The other ones died. I broke the individual plants apart, thinking that they would propagate, but they haven't, so I don't think that's necessary. It floats, so you have to really push the roots down. I think it needs nutrients in the substrate. I stopped vacuuming the gravel, and they are putting out root balls now. Finer, more silty stuff, might work better. The new blades come up from the center, and the ones on the outside die, so it would be best to keep them trimmed off, some of those long handled scissors and tweezers would help. Hair algae tends to grow on the stocks at the bottom. I rub it off. Mine's in a BioCube 16 with stock lights, and 3" of medium gravel (some is sand from the beach - mostly tiny shell fragments). I don't think it needs awesome lights, but it's apparent they like prefer bright light, so that would definitely help. In the Keys turtle grass grows on these "islands" or hills with caulerpa, halimeda, penicillius, and padina mixed in.

I do NOT have a low nutrient tank. I used to. I was having trouble growing caulerpa and botryocladia, so I got two chromis to make more waste for the algae. It worked. I should got a shirimp or something. Now I have hair algae everywhere. I discovered that micro algae really like to grow on macro algae - and grass.

 

[WheatToast]

I do NOT have a low nutrient tank. I used to. I was having trouble growing caulerpa and botryocladia, so I got two chromis to make more waste for the algae. It worked. I should got a shirimp or something. Now I have hair algae everywhere. I discovered that micro algae really like to grow on macro algae - and grass.

Sorry, I did not realize you were trying to keep Sargassum outside of the bucket in you original post. But I still believe that a lack of flow might be weakening the Sargassum (I saw what I'm guessing was your 16 gallon on one of my threads, the only source of flow in the tank appears to be laminar flow from your return jet). Oh, and thanks so much for the seagrass tips! Good read!

 

[BeachWater2]

Sorry, I did not realize you were trying to keep Sargassum outside of the bucket in you original post. But I still believe that a lack of flow might be weakening the Sargassum (I saw what I'm guessing was your 16 gallon on one of my threads, the only source of flow in the tank appears to be laminar flow from your return jet). Oh, and thanks so much for the seagrass tips! Good read!

You're welcome! The tank was an old picture. The bucket is where it is now. It's what I have. I have a powerhead, but in a 2 gallon bucket it would probably be a little too much. LOL. It turns over with the HOB, but it could be better. Eventually, I'll get a second tank. I have an unlimited supply of free sargassum. For now the crab can eat it.

I noticed that when I turn the lights off the sargassum sinks. It must be because the photosynthesis stops and it's not producing oxygen. It comes up to the top when I turn the lights on. The grow light also helped it stay buoyant. I read that it consumes both Nitrogen and Phosphorus, but that Phosphorus was a "limiting" factor in it's photosynthesis. If it doesn't have enough Phosphate, it can't photosynthesize. When I've had it before it stopped floating at all before it turned brown. So, I think that without enough phosphate it stops photosynthesizing, and eventually dies.

 

[WheatToast]

I noticed that when I turn the lights off the sargassum sinks. It must be because the photosynthesis stops and it's not producing oxygen. It comes up to the top when I turn the lights on. The grow light also helped it stay buoyant.

Why do I find this so funny? It’s odd but it makes so much sense!

 

[DrZoidburg]

I had it growing like a weed in low one direction flow under cheap leds. Low nutrient also. The initial stuff I got attatched to shells died completely off forget which species. Then it started popping up with roots on rubble in the tank/sump and I would move it all to sump. Maybe as much as a few weeks later. The spores are in special cells in the plant. They seasonally die off and release those spores. If conditions are right it will magically appear. You could also get it to root by rubber banding it to a rock but that takes seemingly forever.

 

[BeachWater2]

I had it growing like a weed in low one direction flow under cheap leds. Low nutrient also. The initial stuff I got attatched to shells died completely off forget which species. Then it started popping up with roots on rubble in the tank/sump and I would move it all to sump. Maybe as much as a few weeks later. The spores are in special cells in the plant. They seasonally die off and release those spores. If conditions are right it will magically appear. You could also get it to root by rubber banding it to a rock but that takes seemingly forever.

This is the kind that floats in the ocean. I assume they have similar needs, but this never attaches. There's a huge area in the Atlantic called the "Sargasso Sea" where it gets stuck because of the currents. It's been blooming all throughout the Caribbean. It washes up on the beach here in Florida. Apparently there's so much of it in the last 10 years because of excess nutrients from the Amazon. It's really pretty to swim under it and look up at the sun. All kinds of fish and invertebrates live in it and under it.

Warning: At 1:35 the video gets really loud with the waves.

 

[WheatToast]

I had it growing like a weed in low one direction flow under cheap leds. Low nutrient also. The initial stuff I got attatched to shells died completely off forget which species. Then it started popping up with roots on rubble in the tank/sump and I would move it all to sump. Maybe as much as a few weeks later. The spores are in special cells in the plant. They seasonally die off and release those spores. If conditions are right it will magically appear. You could also get it to root by rubber banding it to a rock but that takes seemingly forever.

Do you have any pictures? That does not exactly sound like Sargassum, though I might be wrong.

 

[DrZoidburg]

It definitely was and also from Carribbean. It was the one like you have and also the broad leafed one. The broad leaf one was added some time after died and never came back. Will try to find a picture on old phone I might have one.