Refugiums

[Smallreefer]

So can someone sum up the benefits of refugiums? We agree in general they are not good for nutrient removal. So what are they good for?

Hey, even though i am new to fuges i have read a lot of people saying there good for nutrient export and as wasp said many people use them, And lots of people on rc, have read many good posts on fuges there

Cheers

Dan

[JoeBlog]

The fact is I am not feeding these critters, would not input any less food, or additions if I did not run a refugium...

Doesn't this above statement imply that there are extra nutrients available in the tank (not being exported) since the critters in the fuge are being supported without any addition of more food? Given that there are nutrients in the system for them to eat, aren't they going to poo as well? Doesn't this whole process fall under bio-load?

the critters that thrive in the ref...

When I think of thriving, I think of a very well populated colony of critters. The fuges that I've seen that would be considered "thriving" basically look like the sand itself is moving and that is only the top layer that we can see. Would that not constitute a significant bioload?

OK, OK,... Regardless of whether it is a "massive" bioload or not (although still some extent of a bioload), I am curious as to the actual benefit of a fuge, and thus whether this benefit outweighs the additional bioload that could be substituted for more fish. From the article presented above, there are four basic reasons:

1) Nutrient Export: it seems to be agreed that they are not ideal for this purpose given alternative means available.

2) Grow things to feed your tank, e.g. pods, algae, etc… Can’t the hobbyist provide the same quantity and quality of food to the tank without a refugium? I can certainly grow live food outside the display system. If the fuge isn’t there, then any excess nutrient can also be directly removed if not consumed by fish and coral. Therefore, I wouldn't need the additional bioload created by the refuge to simply feed the tank, and thus could support more fish with my system.

3) pH stability with reverse lighting: I personally don’t worry about pH swings and only focus on keeping dKH stable. So, this is a non-factor for me, but may be a benefit to others. If people are concerned about having pH swings, are there other methods of controlling them without adding any additional bioload?

4) Increase the overall size of the system, i.e. additional water for greater stability. Again, you can have an area for additional water without creating a place for nutrients to collect and thus critters to feed off these nutrients and thus additional bioload, e.g. a bigger sump with nothing in it except water. Personally, I would rather have a bigger main system than more water behind the scenes, but this may not be an option with space constraints in the viewable area.

Well, those are all the reasons/benefits listed in the article. Are these “benefits†great enough to outweigh the cost, i.e. additional bioload from critters and thus fewer fish? Given the above, I think it is for me. However, it appears that some people value having these little critters as diversity (pets). That may be reason enough to have a fuge. Like I said, I would rather have more fish!!

Are there other benefits that the article and I am missing?

[puttputt]

benefits of a refugium

- A refuge for pods, shrimp, worms etc to live, breed , multipy without preditation and the export of this life into main tank - proven that 90% of pods can pass through pumps. If these animals are breeding, think of the tiny (plankton) live food getting to your display.

- remote running of a sand bed, giving the ability to moniter and change this sand bed simply without disrupting main tank.

- possible nutrient reduction, but limited to high nutrient tanks, better suited to fish only for this.

- putting bad blue legged hermits that keep knocking your acros over, and hairy gorilla crabs that you dont have the heart to kill.

[puttputt]

posted at the same time joe blog,

- I would think that the extra nutrients are being tied up by the critters before they can be exported, other wise with effective skimming they would be exported. I never said that there is no increase in bioload, just question how much. My sand doesn't heave with life , somewhat of a scary thought if it did, but the surface of the sand, and the glass, and the rock in there teems with pods and shrimp. I also think you can underestaimate the value of this type of food, as opposed to you adding dead or dryfood.

I don't think there is a clear yes or no answer, i guess the results of each persons system speak for themselves.

[JoeBlog]

benefits of a refugium

- A refuge for pods, shrimp, worms etc to live, breed , multipy without preditation and the export of this life into main tank - proven that 90% of pods can pass through pumps. If these animals are breeding, think of the tiny (plankton) live food getting to your display.

- remote running of a sand bed, giving the ability to moniter and change this sand bed simply without disrupting main tank.

- possible nutrient reduction, but limited to high nutrient tanks, better suited to fish only for this.

- putting bad blue legged hermits that keep knocking your acros over, and hairy gorilla crabs that you dont have the heart to kill.

Can't all of these things be accomplished without the additional bioload of a typical refuge? I've addressed all of them above except for:

-area for sand bed that is easy to replace. If you want the sand bed for bacteria and nitrate reduction, then a RDSB will accomplish the same without the bioload of all the critters associated with accumulating detritus.

-area to place unwanted or injured animals: this can be done in a sump that is kept clean, i.e. not a place for detritus to accumulate as is the case for typical fuges.

[puttputt]

Like I said, I don't think there is a right or wrong way. Stick to what works for you. I would rather run a bb tank with a sand bed in a ref with lots of critters, as I do now, and believe the benefits out way the negatives. I don't believe it is increasing my bioload substantially and don't limit corals or fish in my display because of it.

You may want to breed live food externally, run remote DSBs, larger sumps etc to get the same benefits. I'm sure your new tank will be a success as well.

I seen a number of tanks up here in Auckland all running differnt systems and theories, e.g. Crackers tank. I run a very different sort of tank to Craigs but we both have very good results.

[JoeBlog]

I would think that the extra nutrients are being tied up by the critters before they can be exported, other wise with effective skimming they would be exported.

I am making assumptions on bioload. I would think that the critters are eating something and then poo some time later, and thus creating bioload.

I am running an ap902 with a direct feed from the overflow. The water exiting the skimmer then goes through a filter sock. It is incredible the amount of crap in the sock each day. If I leave it for just two days, it is overflowing due to being clogged with detritus. I would say that on a 150 gallon system that an AP902 is effective skimming, but still all that crap is getting by the skimmer and would settle in my sump (if I didn't have the filter socks), which I guess could then be called a fuge since there would surely be heaps of critters in there eating all the crap (pooing) protected from predation of tank inhabitants.

I never said that there is no increase in bioload, just question how much.

Sorry, I didn't mean to imply that you said there is zero bioload. I agree that the BIG question is "how much" of a bioload does the fuge create.

My sand doesn't heave with life , somewhat of a scary thought if it did, but the surface of the sand, and the glass, and the rock in there teems with pods and shrimp.

I have seen quite a few tanks with just insane amount of pod life, and I agree that it is scary!

I also think you can underestaimate the value of this type of food, as opposed to you adding dead or dryfood.

I also agree, but you don't have to only feed dead or dryfood. You can easily grow brine shrimp outside the tank. I used to go to the beach once a week and get a bucket full of little critters to feed to the tank. The point is that these critters don't need to be grown IN the tank and thus add to the bioload.

I don't think there is a clear yes or no answer, i guess the results of each persons system speak for themselves.

Totally!

[JoeBlog]

Like I said, I don't think there is a right or wrong way. Stick to what works for you. I would rather run a bb tank with a sand bed in a ref with lots of critters, as I do now, and believe the benefits out way the negatives. I don't believe it is increasing my bioload substantially and don't limit corals or fish in my display because of it.

You may want to breed live food externally, run remote DSBs, larger sumps etc to get the same benefits. I'm sure your new tank will be a success as well.

I seen a number of tanks up here in Auckland all running differnt systems and theories, e.g. Crackers tank. I run a very different sort of tank to Craigs but we both have very good results.

Very true!! In fact, your tank has been making me a bit depressed lately. We are running very similar systems and your colors are heaps better than mine!! Maybe I do need a fuge!!

I was basically just thinking out load trying to figure out if it would be a good idea putting one on my new tank. My buddy helping me out with the designs, etc... has been pushing pretty hard for it. He claims that my colors are crap since the system is nutrient deprived. I've been buying into that a bit and thus all the questions.

He actually has this theory of "dirtier = cleaner... to a given extent" mainly directed at BB systems with crazy nutrient export in place. I've been trying to get him to post his thoughts, but haven't been successful yet. Maybe this will bring him out of the woodwork!

[wasp]

Why do people say a fuge adds bioload??

This would depend entirely on how it was set up & for what purpose. If it was purely set up for nutrient export, forgetting critter farming etc, it would just be a bare tank, with just enough rock to give the macro algae a grip, and a heap of macro algae strongly lit. The macro algae would then be harvested as needed to remove any surplus nutrients from the tank, I do not see how this would "add bioload". It could also be run reverse photoperiod to raise pH at night.

The only way I see a fuge "adding bioload" would be if it was designed that way, in order to farm critters. However that would be a choice someone would make when setting it up, for whatever purpose they intended it for.

[JoeBlog]

Why do people say a fuge adds bioload??

This would depend entirely on how it was set up & for what purpose. If it was purely set up for nutrient export, forgetting critter farming etc, it would just be a bare tank, with just enough rock to give the macro algae a grip, and a heap of macro algae strongly lit. The macro algae would then be harvested as needed to remove any surplus nutrients from the tank, I do not see how this would "add bioload". It could also be run reverse photoperiod to raise pH at night.

The only way I see a fuge "adding bioload" would be if it was designed that way, in order to farm critters. However that would be a choice someone would make when setting it up, for whatever purpose they intended it for.

I agree that the strict definition of refugium is simply a place void of predators. A bare sump could certainly be a refugium. If you could keep the detritus out of the refugium, then I agree that there won't be any bioload since there isn't anything for them to eat.

If it was set up for nutrient export with rock, algae, etc..., again the only way that it wouldn't become a critter farm is if you kept the detritus out of there, e.g. ran filter socks. If detritus does reach the refugium, then so can critters. Therefore, you would have bioload. No???

Just as you said Wasp, depends on how you set it up.

Cheers,

Steve

[Feelers]

I've just been having some lectures on soil microbiology, its surprisingly interesting. :lol:

Anywho - the biomass of a dsb is probably very large. I'm drawing a comparison between a sand bed and terrestrial soil but I think thats actually a reasonably fair comparison to make. (this is to a depth of 10 cm)

SO - some cool WOW facts they love to throw in, the total biomass of microorganisms in a 100m x 100m square (hectare) is approximately 3000 to 4500 kg. The number of bacteria in that hectare is 100,000,000,000,000,000,000 or 15 billion times the human population.

However - biomass is different from the idea of bioload. While sand beds have such a big biomass their bioload is obviously much smaller. Since tanks still survive well with a DSB added, that tells me the sand bed isnt out competing everyone for oxygen/nutrients.

The biomass in the bed is a way to recycle nutrients back into the tank in a useable form - pods etc, out of what is available in the system. It cant be counted as load as say an additional fish or coral would. I definitely think pods etc are far better food than the typical foods people offer their tanks.

You can use it for nutrient export though - run a dsb and it will take years to fill, at which point you can just disconnect it and replace the sand.

[wasp]

Good post Feelers.

Looks like some really interesting stuff you're doing at Uni! Wish I'd done something like that!

[Feelers]

Oh -another cool one; the average bacteria divides only once a year, they spend a total of 7 hours reproducing and the rest of the year sitting around doing nothing but maintence, (insert the life of a reef keeper joke). :lol:

Biofilms (what we are looking at the moment) are incredibly complex - ie the slime on the inside of the tank wall. Complex 3-d structures in which the bacteria live together and share problems and DNA between completely different genuses.

Apparently there's loads of DNA just sitting round everywhere, and microbes just pick them up and use them - human genes also.

I love being able to watch them cruise by in the microscope, just puttering around crashing into everything, very surreal.

[Fay]

As a matter of interest how many of us run a fuge of any type.

I know Pies has a big one.

then there is Reef, Cracker, Hollywoods, Fay, Puttputt, Skippy, Steve West, Ira, Chimera, suphew,..............

Have I missed anyone?

[Fay]

11 of us so far!!

[puttputt]

skippy...

Steve Weast (i guess he posts on this board so one of us )

[petplanet]

Oh -another cool one; the average bacteria divides only once a year, they spend a total of 7 hours reproducing and the rest of the year sitting around doing nothing but maintence,

So how does a tank cycle so quickly? Is it just bacteria moving in to a suitable enviroment as opposed to bacteria reproducing?

I am planning on using a 4 foot for a refuge. Mainly to grow algae and pods so the fish have rocks with more life on them to pick over. The added bonus will be nutrient export if the algae growth goes to well.

[chimera]

As a matter of interest how many of us run a fuge of any type.

yup. but personally wouldnt run macro algae again.

[Ira]

As a matter of interest how many of us run a fuge of any type.

I know Pies has a big one.

then there is Reef, Cracker, Hollywoods, Fay, Puttputt,..............

I did/do sort of. Not so much a fuge now as a sump full of liverock, used to be full of macroalgae but I did a big cut back and it hasn't grown back. Need to replace its lights though.

[wasp]

I used too, the algae faded away and so did all the critters, after I started using the bacterial nutrient reduction system I'm using now. Bacteria, with suitable support such as the zeovit system, are able to scavenge nutrients to lower levels than macro alge require for survival.

So eventually I dispensed with the fuge.

I do miss it though I enjoyed it nearly as much as the main tank, on the down side it was another thing that upset my wife from time to time. Why I'd be up 3 hours late at night looking at it with a torch. :lol:

[Feelers]

So how does a tank cycle so quickly? Is it just bacteria moving in to a suitable enviroment as opposed to bacteria reproducing?

They can rapidly exploit beneficial situations, so when you put in new rocks for them to colonise and nice warm water they will reproduce quickly -probably doubling every hour or so. The first bacteria (amonia feeders) will create a biofilm, and their waste (nitrite) will attract the nitrite feeding bacteria to join them etc. They rapidly get to the point of maxium saturation, and thats where things stay. After you tank is cycled the amounts of bacteria stay roughly the same, and they are back into the 7 hour reproduce/365 day resting stage.

[wasp]

Feelers, a question on nitrate reduction -

When the nitrate is created presumably in the biofilm at the rock surface, will the nitrate, or much of it, be consumed by nitrate eating bacteria, slightly inside of the rock, before it even enters the water column?

And next question, nitrate that actually does get into the water column, does that have to somehow get to within the rock to be reduced, or is there any other way?

Please if you have not yet fully done all this stuff, no worries, but for now, you seem to be "the man" for this type of info.

[Feelers]

Am am only just learning about these things - I think the take home message has been that there really arent too many rules, as the situation has so many vairables its almost impossible to grasp.

But, I would imagine they all live together, and pass their waste to the next in line. The conditions within the biofilm can also vary greatly - you can get low oxygen levels just by hanging out in the middle, I think anoxic conditions are actually possible(not too sure on this point) but probably not in great enough levels for a tank, which is why you need the thick rock. Nitrate might even be passed on between non nitrating bacteria into the rock to get to where it's needed.

The full reduction of Nitrate to Nitrogen is pretty complex, the reason this ability isnt spread between microbes is probably because there are many genes involved.

Only way to see is the have a tank with no anoxic conditions and see what happens! :lol: Has this ever been tried?

[wasp]

Thanks

[suphew]

I have live rock in my sump wth a ton of live on it, does this count?? no sand or micro algae.