[Pomme]

Macro algae or mangroves?

I have been thinking of having a macro algae section in the sump to complement the skimmer.

But i was reading today in one of my books that mangroves can be just as good if not better then maro algae. I have heard many people saying that mangroves are no good at nutrient export. But i read that they need weeks to acclimatise to the aquariums conditions, 2-6 weeks, and then they dont have there full impact on water quality untill 3-6 months. So could it be people dont like them becuase they dont have an immdeiate impact on water quality. I can see a few advantages of mangroves over macro algae, in that it doesnt go sexual, ie caulerpa, and it doesnt need harvesting as much, ie caulerpa or chaetomorpha.

So what do you guys about both the macro algae and mangroves.

Andrew

[Ninong]

I think mangroves are very cool looking and I would love to have some if I had a really large system with a really large, well lit refugium. However, I doubt very much that a few mangroves would be as effective at nutrient export as macroalgae that is harvested weekly.

Someone I know who has a lot of experience using macroalgae in his refugium for nutrient export tells me that it is better to have four or five different species so that if one of them just happens to go sexual at least the problem will not be a large as if your entire population of macroalgae went sexual at the same time. Pruning the macroalgae on a regular basis is reputed to prevent it from going sexual.

[Reefland]

The problem with mangroves for nutrient export is their slow growth; it would take a much larger population of them to have the same effect as a "refugium" full of macroalgaes.

Scott Z.

[Pomme]

yeah thats what i heard but i have just read a report from a uni over here which has done some tests on mangroves, on it says that after the acclimatisation period the mangroves lower the levels below what macro algae, can becuase when the macro algae can only lower it a certain amount becuase it always leaves a bit so it can gow otherwise it dies, and the mangrove can lower it below this level.

Andrew

[Elmo18]

I would prefer macroalgae as well with pruning on a regular basis, as it need be. With mangroves, you also need to wipe their leaves off since they build up salt creep on them.

So i guess both need maintenance, but macros does grow faster as mike has said and you can give what you prune to your friends

- Elmo

[Pomme]

yeah i have decided to go for both

i will have two sumps available, both around 20x20. one will be devided in two and have caulerpa in one section and caheto in the other. The other one will have mangroves and around 30" above the water surface for them to grow

[fishgeeksrus]

We have both!I posted two pictures

one from Feb 04
and one Jun 04

[SurfStone]

looks like you are ready to plant your mangroves. the roots are getting very long. I have heard some stories of people no longer using their protein skimmers because they ceased to fucntion as soon as the mangroves were acclimated and growing really good. they number of mangroves is not as important as the size of the root ball the more roots the more the mangrove takes out tds, nitrates, and phosphates. wiping mangrove leaves once a week is a lots easier than harvesting macroalgae IMO. I use both and I love both. However I still use my skimmer. But the former was tested buy reputable people (G.A.R.F). Just my .02. Good luck.

[kevinpo]

I think mangroves are more of a novelty than useful nutrient export in most cases. They need much more light than other plants. They also grow very tall. Chaetomorpha works much better and is pretty much set and forget.

I have mine planted in the main tank now because it grew too tall in the refugium (after 2.5 years). Their export capability is really a function of the size ratio of the tank to the tree. Most of their benefit is through their root system, which removes nutrients from the sand bed. My tree is about 30" tall and has a root system about 12"x12". They are not going to adsorb many nutrients directly from the water column as well as other macro algae but are still very cool if you have the room. They can be difficult to acclimate to saltwater, as many places grow them in brackish water rather than saltwater.

Regards,
Kevin

[FragGuy]

Mangroves are a nice novelty. That's about all. Studies are showing that pound per pound they don't come close to macro algaes in their ability to absorb nutrients. If you are not harvesting a fair amount of algae and you know your system has high nutrients then the export process isn't working.

I'm not saying not to keep them. I'm just saying that they are not going to be as efficient if your primary goal is nutrient export.

Rafael

[smidoid]

Originally Posted by kevinpo

I think mangroves are more of a novelty than useful nutrient export in most cases. They need much more light than other plants. They also grow very tall. Chaetomorpha works much better and is pretty much set and forget.

Still waiting for peer-reviewed papers on all this - in the meatime, since we're all arguing it - where does one get "Chaetomorpha" (and does it have a common name - I have enough trouble with Caulerpa...!

[greenbean36191]

You probably won't find any peer-reviewed papers about nitrate reduction my mangroves. Outside of the hobby, no one really cares since that's not the primary impact of mangroves on water quality. I suspect that someone in the hobby read about how destruction of mangrove swamps was leading to "dirty" water killing off corals. In nature, the mangroves are primarily removing sediment from the water column, not nutrients. As with most true plants, most of the nutrients mangroves take up comes from the substrate, not the water column.

I haven't tried it, but I suspect that if you had an equal mass of macroalgae and mangroves and dosed them the same amount of nitrate you would find that the algae is much more efficient at taking it up. The only tests I've seen compare arbitrary amount of macroalgae and mangroves, so aren't really controlled tests. Most tests I've seen also use substrate for the mangroves and none for the macroalgae, which further skews the results.

[smidoid]

I have read at least one story that claims that mangroves did the trick. The problem with stories like this is that there is no "control". IF I had the space (or lived on my own) I'd set up a test base to see what happens with some mature water from water changes and grow each side by side. This is the sort of thing some of us can do - but it does take some effort and my wife won't let me have the plants on show.

[kevinpo]

where does one get "Chaetomorpha" (and does it have a common name - I have enough trouble with Caulerpa...!

Here you go
http://www.liveaquaria.com/product/p...fm?pcatid=2401

Cheers,
Kevin

[smidoid]

Ah! Spaghetti Algae! Neat. I'm going to try and see if I can get some.

I got some Caulerpa on the last batch of LR but I wasn't sure what it was until I got it home and in the tank. It's the stringy one and it's going in the bin shortly - right now I'm keeping an eye on the growth to see what it does!

[Ninong]

Originally Posted by smidoid

I have read at least one story that claims that mangroves did the trick. The problem with stories like this is that there is no "control". IF I had the space (or lived on my own) I'd set up a test base to see what happens with some mature water from water changes and grow each side by side.

All you really need to do is think about it for a few minutes and the answer becomes obvious.

Just go back and read what has already been posted in this thread. As Greenbean has already pointed out, mangroves are plants. They get their nutrients through their roots. Algae do NOT even have roots. They absorb nutrients directly from the water column.

The whole idea here is to export nutrients. You can't export anything unless you remove it from the system: Export! When you remove Chaeto from your sump, you are exporting nutrients. The only way you can export nutrients with mangroves would be to remove leaves and throw them in the trash or maybe prune the branches every year or so. Other than that, the nutrients are tied up in the plant tissue and remain in the system although sequestered until the plant dies and decomposes.

If you set up a really large refugium, say a 300-gal Rubbermaid tub, and then grow a half dozen or more mangroves to a height of 6 or 8 feet, you might be able to tie up a considerable amount of nutrients over a period of time but you would still be better off with algae. Algae grows much, much faster than plants.

Mangroves are cool looking but they do little in the way of nutrient export. Macroalgae that is fast growing and can be harvested every week or ten days would be much more effective.

[smidoid]

Yeah. Makes sense! ;0)

Occam's razor anyone?

Pity that - seemed like such a good idea. <sigh>

[Which also makes me think, you can re-cycle the algae by putting it back on the composter and fertilize the garden!]

[firefox]

Hi

the use of plants as filters is a very well established method for fresh water . iris and reeds can turn the most poluted of water in to almost drinking quality . The chemistry is complex and harvesting is not always nescessary ,though the production of reeds for thatched roofing is a very usefull by product .
If the mangrove tree locks up tha nitrates and stuff then job done it has been exported from the water which is what you want.

I fully agree it would take some serious testing and because you are using compleatly different methods and enviroments comparisons would be difficult . I think that sucsess with mangroves is hampred because they do not live in pure full strength sea water all the time giving rise to , oh they always die . Now would they like to live in some kind of tidal arangement where the salt water was drained for a time and flushed with fresh water ,during this time would alsorts of osmotic stuff go on and the tree rebalances its chemistry ? should be something for the DIY guys .thus making it more able to take up the junk

The perfict filter is still to be found and we all contribute to the surch for this and put two reefers in the same room and you will have three opinions
if it works for you tell the rest of us if it dont tell the rest of us

Firefox

[smidoid]

Hello Firefox! Watford eh?! We're neighbours on this scale!

I hear you can acclimate mangroves to full-strength seawater, but I don't know what the results are like. The also absorb some salt which affects the SG. Ummm...

Spaghetti seems like a safe bet (safer than caulerpa, for instance) and it does give somewhere for other life to rest and breed. Still, I remain intrigued by the mangrove if for no other purpose than it's exceptional root system.

[sihaya]

I have mangroves in my refugium, but not for nutrient export (which, as others have said, they aren't useful for). I just used them for decoration and to hold the macroalgae in place.