Filtration Via Xenia

[TJ_Burton]

Alright, so the question is raised: Do xenia have a role in filtering our aquariums?

I personally do not know the answer. What I do know however, is that I have seen 20g prop tanks on larger systems that were filled to the brim with nothing but xenia, claiming that this was a good way to help "filter" the water. Filter the water of what? I have no idea; I assume extra nutrients. I do also know xenia does much better in aquariums that have less then immaculate water, which leads me to believe this "xenia filter" may have a place in reef aquaria.

 

Now, the reason I bring this up is because on my new 40g system, I can potentially have two 20g prop tanks. One intended for frags, and the other is still up in the air. The 40g sump will have at least 20g dedicated to a refugium, and the left over space for an over-sized skimmer. I am trying to figure out if it would be worth my while to use the remaining 20g prop as a xenia filter. Aside from having xenia frags at the ready on a constant basis, if they are actually a viable source of nutrient export I would be willing to give it a try. I plan on having quite a few fish, and I feed my tank quite a bit, so I won't be short on excess nutrients.

 

So here we go folks,

Lets get this discussion rolling!

[psam]

Might remove DOM, but they don't trap large particles. One concern I'd have is if the colony decided to crash. With a large amount of Xenia, might be pretty rough on the tank. I'd be hard pressed to imagine that Xenia can do a better job removing nutrients from your tank than chaeto, though you could pull them out and sell / trade large frags, so more desirable in that aspect. Another thing is that xenia needs light. If looking for some biological filtration, I think a cryptic zone would be a better option, and aside from not requiring the extra lighting that xenia does, some of the animals in there will trap particles that xenia may not. If you look around GARF, they have a page on xenia filter. One of the TOTM on RC, maybe 5 or so (maybe more?) years ago was using xenia as a filter...

[TJ_Burton]

Might remove DOM, but they don't trap large particles. One concern I'd have is if the colony decided to crash. With a large amount of Xenia, might be pretty rough on the tank. I'd be hard pressed to imagine that Xenia can do a better job removing nutrients from your tank than chaeto, though you could pull them out and sell / trade large frags, so more desirable in that aspect. Another thing is that xenia needs light. If looking for some biological filtration, I think a cryptic zone would be a better option, and aside from not requiring the extra lighting that xenia does, some of the animals in there will trap particles that xenia may not. If you look around GARF, they have a page on xenia filter. One of the TOTM on RC, maybe 5 or so (maybe more?) years ago was using xenia as a filter...

 

Thats the one I remember seeing, from RC TOTM. What sort of animals would you suggest to use for a cryptic zone. I am not familiar with the term.

[psam]

Non-photsynthetic animals / filter feeders - sponge, sea squirts, tunicates, some feather dusters. Do a search for cryptic zones and Tyree's Environmental Gradient, pretty cool stuff.

[travisurfer]

xenia has a higher concentration of organic wastes in its tissue than caulerpa.

[TJ_Burton]

xenia has a higher concentration of organic wastes in its tissue than caulerpa.

 

I apologize for the ignorance, but I don't quite understand what you are trying to say.

[psam]

That doesn't necessarily mean xenia removes as much DOM as caulerpa - it doesn't grow as fast, so it wouldn't be harvested as often, so the organic materials stay in the tank. On that note, I wouldn't use caulerpa for nutrient export either, would make me nervous.

[shiveley]

do a web search...it's been experimented with with varying results.

 

http://www.garf.org/28/xenia/2/xenia914.html

 

XENIA BED FILTER REPORT.

 

We have been testing a new filter that uses many species of Xenia to filter the water in our 150 gallon SPS coral brood stock tank. This filter is now four months old and it is doing a very good job. GARF now has over a dozen different types of Xenia in our genetic bank. We have recently imported several new types of Pom Pom Xenia from Tonga. We are reminded just how difficult it is to domesticate a new wild collected pulse coral. The Xenia that we have imported do not grow or pulse as well as the strains that we receive each week in our trade program.

 

When we set this system up we will be able to remove cleaned water as we add nutrient rich water from the 500 gallon SPS system. We will not set this system up as a Xenia Bed Filter because we want to learn how fast we can grow adult Xenia colonies with the new food we are testing. We are certain that the Xenia will absorb the nutrient that are produced by bacteria as they consume the food.

[TJ_Burton]

That doesn't necessarily mean xenia removes as much DOM as caulerpa - it doesn't grow as fast, so it wouldn't be harvested as often, so the organic materials stay in the tank. On that note, I wouldn't use caulerpa for nutrient export either, would make me nervous.

 

I personally use 3 strains of caulerpa and chaeto in my refugium. I do not mind have to pull it out regularly, as I have been doing it since I started with reef tanks, but if it were a decent exporter, I would add xenia to the mix. DOM = Dead Organic Matter? That was a shot in the dark, I am trying to catch up on the abbreviations.

 

Also, I am definitely considering a cryptic tank. They would make a very interesting display on top of the benefits.

[jamesnmandy]

xenia in my tank is the only way i can explain my nitrates have fallen since my tank just went through a mini cycle after moving into a larger tank and adding more LR and sand as i havent changed any water yet

 

i also read somewhere that they do remove noticeable amounts of nitrites

 

so i have a love/hate relationship with my elongata, its great but it grows out of control and has to be weeded out every few months

[psam]

That info (GARF link above) is from 1999, at which time it was 4 months old. I can't seem to find any of their results posted?

[TJ_Burton]

xenia in my tank is the only way i can explain my nitrates have fallen since my tank just went through a mini cycle after moving into a larger tank and adding more LR and sand as i havent changed any water yet

 

i also read somewhere that they do remove noticeable amounts of nitrites

 

so i have a love/hate relationship with my elongata, its great but it grows out of control and has to be weeded out every few months

 

I used to grow elongata in a skimmerless tank faster then I could pull it out. One the other side of the fence, my tank with a skimmer had barely any growth. This may not be causal and just coincidence, but it is worth investigating.

[jeremai]

I've been experimenting with the cryptic thing for a little over a year now, with mixed results. I've talked to people who have used it with success on larger tanks, but it just doesn't cut it less than 50g, imo.

 

I've had the Xenia idea nagging at the back of my mind for a while, though. I'm interested to see where this thread goes. Any nutrient uptake studies out there? I remember seeing one for Stylophora, I'm sure there's one for Caulerpa... not sure about Xenia. And I'm too lazy to search.

[JG]

I have plenty of nutrients and my nitrates never measure anything since I put it in. I also have cheato but my nitrates where elevated with just the cheato.

[OB1]

I heard a couple guys talking about letting their fuge fill up with aptasia. Would this be in line with the cryptic thing? Could aptasia remove larger particles than xenia?

[MrAnderson]

Xenia is an extremely efficient exporter of nitrogenous waste in the form of ammonia. By weight, it removes ammonia and total kjeldahl nitrogen more efficiently than Caulerpa.

 

http://www.reefkeeping.com/issues/2002-12/...ature/index.php

 

Table 5 provides the salient data points.

 

(FYI, total kjeldahl nitrogen [TKN] is the total of organic nitrogen)

[jamesnmandy]

i think i know what i am going to put in my fuge when i get it set up now.....some sand and LR rubble and all of the xenia i cut out of the show tank....which will no doubt multiply quickly and fill it up.....i am convinced now that the xenia in my tank does explain why my nitrates are coming down on their own after that mini cycle.....thats the only explanation i can come up with and it makes even more sense now

 

anyone know if once the xenia completely runs out of room in the fuge if it will stop growing or will it continue to grow until it chokes itself and crashes in the fuge...???

 

i could prune the fuge xenia too.....but i was just thinking, if it stopped growing after a point, i could just have a fuge slap full of xenia and not have to worry about it....

[jeremai]

Thanks for the link, MrA.

 

Export efficiency may be measured in a couple of ways, however, and although on a per weight basis Xenia appears to be the best export mechanism, Caulerpa grows far faster in most tanks and it would accumulate a lot more of the needed export per unit time.

 

I've never had Xenia before. Is it prone to dying suddenly? Everyone hypes it up like they used to hype Caulerpa going sexual. Seems to me if you take care of it by keeping the tank stable and the Xenia pruned, why would there be a problem?

[SPS20]

I think it would be fairly important to run activatd carbon to help reduce allelopathy. Having a whole lot of any one species in a tank can stunt or kill some other corals if allellopathic toxins are allowed to accumulate unchecked.

 

Tridacnids, in particular, are known to be stressed by certain chemicals that Xenia produce, and produce excess mucous in the presence of Xenia as a result.

 

See here: http://www2.hawaii.edu/~delbeek/reefaq6.html

 

Xenia colonies have been known to crash, but many people believe that the use of lugol's iodine can help prevent this. Regular water changes, of course, also help.

 

Some species of Xenia do grow incredibly fast under the right conditions, so I would imagine it would be possible to sustainably harvest a fair amount of biomass every week, thus removing a significant amount of nutrients from the system.

 

- Josh

[TJ_Burton]

I think it would be fairly important to run activatd carbon to help reduce allelopathy. Having a whole lot of any one species in a tank can stunt or kill some other corals if allellopathic toxins are allowed to accumulate unchecked.

 

Tridacnids, in particular, are known to be stressed by certain chemicals that Xenia produce, and produce excess mucous in the presence of Xenia as a result.

 

See here: http://www2.hawaii.edu/~delbeek/reefaq6.html

 

Xenia colonies have been known to crash, but many people believe that the use of lugol's iodine can help prevent this. Regular water changes, of course, also help.

 

Some species of Xenia do grow incredibly fast under the right conditions, so I would imagine it would be possible to sustainably harvest a fair amount of biomass every week, thus removing a significant amount of nutrients from the system.

 

- Josh

 

Josh, do you think it is worth trying?

[SPS20]

Josh, do you think it is worth trying?

 

Sure, why not? I used to have a 120 that was at least 1/3 dominated by Xenia, and my other corals were ok, so I don't think it would be a terrible idea. I did run alot of carbon on that system (and every one since) so I never had any significant problems with allelopathy. The only reason I posted what I did is so that anybody trying it would be aware of potential issues, not to dissuade you from trying.

 

I find it hard to believe that having that much of anything which grows as fast as Xenia wouldn't remove alot of organic matter from the system if harvested on a regular basis.

 

Not only that, but you could easily harvest a couple of nice Xenia colonies weekly from such a setup, and that's good for trading/selling to support your reefing addiction.

 

It's certainly a heck of alot cooler than chaeto. Mr. A's article above certainly would seem to indicate that it can work, if done right.

 

If you look carefully at the data in the article, especially the last couple of tables, you will see that, although Xenia grows at about 1/4 the rate of Caulerpa in terms of raw biomass, it is much, much "richer" in organics by weight, and is much more efficient at removing heavy metals such as copper. Coupled with some carbon, this idea has the makings of a very efficient system for the exporting of toxic metals and organic waste. At least, on paper.

 

- Josh

[TJ_Burton]

Sure, why not? I used to have a 120 that was at least 1/3 dominated by Xenia, and my other corals were ok, so I don't think it would be a terrible idea. I did run alot of carbon on that system (and every one since) so I never had any significant problems with allelopathy. The only reason I posted what I did is so that anybody trying it would be aware of potential issues, not to dissuade you from trying.

 

I find it hard to believe that having that much of anything which grows as fast as Xenia wouldn't remove alot of organic matter from the system if harvested on a regular basis.

 

Not only that, but you could easily harvest a couple of nice Xenia colonies weekly from such a setup, and that's good for trading/selling to support your reefing addiction.

 

It's certainly a heck of alot cooler than chaeto. Mr. A's article above certainly would seem to indicate that it can work, if done right.

 

If you look carefully at the data in the article, especially the last couple of tables, you will see that, although Xenia grows at about 1/4 the rate of Caulerpa in terms of raw biomass, it is much, much "richer" in organics by weight, and is much more efficient at removing heavy metals such as copper. Coupled with some carbon, this idea has the makings of a very efficient system for the exporting of toxic metals and organic waste. At least, on paper.

 

- Josh

 

Then it has officially made my list of possibilities for the new system. I will have to do some more research and planning into the subject.

[jamesnmandy]

update on my tank parameters as it relates to the topic:

 

in 3 days time my NO4 has dropped from 20ppm to 5ppm with nothing but a skimmer hanging off the back, no sump, no fuge, no mechanical filtration otherwise, for filtration...and the 5 or 6 large heads of elongata xenia, 100 or so zoo polyps, and one large torch coral

 

nitrites also have dropped along with the NH3

[shiveley]

I've had perfectly healthy colonies of xenia crash for no apparent reasons when my tank's parameters seems to be spot on. I have to say that I can't really see a reason to use xenia over chaeto considering the problems that would be encountered should the xenia spontaneously begin to die off. chaeto's almost bullet-proof with regard to the negative impact it can have on a tank; the same cannot be said of xenia, however.

[jamesnmandy]

I've had perfectly healthy colonies of xenia crash for no apparent reasons when my tank's parameters seems to be spot on. I have to say that I can't really see a reason to use xenia over chaeto considering the problems that would be encountered should the xenia spontaneously begin to die off. chaeto's almost bullet-proof with regard to the negative impact it can have on a tank; the same cannot be said of xenia, however.

 

 

and just to offer an opposing viewpoint...

 

in my 35 gallon tank, at the time which was about 1/3 full of xenia, before i knew about their toxic release when stressed, i had both arms in there and was just grabbing them and squeezing them at the base and pulling them off the rocks.....and the water turned a bit cloudy, and with the help of the skimmer within a couple hours it was clear again and no harm done.....go figure..