20long Dragonet Tank

[MiltonP]

I have a 20L that I want to turn into a dragonet, ie...Mandarin, species tank. I am planning on a 2"-3" ls bed with 20+ lbs lr. Mandarins love copepods so I was thinking that a 12 CPR refugium with a ls bed and macroalgae might be a good addition. What else do I need to make the mandarins and their copepod food supply happy? I was also wondering if sectioning off one end of the 20L for the refugium might be as good or better than adding the CPR 12. I am also debating a skimmer but prefer to pull off an all-natural solution if possible.

I posted here because I figured if you all can keep coral happy in Picos, you wouldn't consider me an idiot for trying dragonets in a 20L. 8O Thanks Milt

 

[brandon4291]

no I wouldnt scoff at you for that, and let me get in here before someone else does. Glad you posted in this forum, you'd be attacked by savages out in the general playing field



this is all just my humble opinion and very lengthy tonite:

as far as a 20 long packed full of aged LR, I do think it will process the ammonia/nitrogen internally from the fish (one is not so bad, two may be too much bioload for an unskimmed tank but I dont know) without a skimmer provided you have good current. Theres enough surface area in there to do so. A fine balance it will be, but nothing 50 percent water changes once a month wouldnt reset (nitrate levels) for the next 4 weeks. Less water changes if you make a large baffled refugium and fill it with aggressive macros (brightly lit--a must IMO).

IMO you should set up the system just like you explained, but let it run 4 months until you put in a dragonet. Shorter time to get ready if you'll buy or find a seeder kit with various grammarus, copes etc. Feeding your arthropods regularly cannot be understated. They will grow (in numbers) proportionately to your feeding regularity, to the point of swarming your rocks at all times. This is how it should look before a fish that predates them is installed./

No matter what people say, if your dragonet eats and stays well-rounded he is doing fine in there. If he behaves any differently than in a larger system, suspect something of yours.

It is the trick of keeping copepod numbers high and in regular production that challenges you in this setup. A separate refugium, especially a large one (25 percent of tank volume, lots of stacked lr and macro, blocked from fish) would provide quite a haven for them.

I think it can be done---the solution is very simple. Just agree to take him out if he stops eating or runs short on food, then no one can cry about the idea. I know people that are feeding mandarins enriched brine shrimp (supplement to tank copes) and they have been doing fine for many months. Good Luck, I believe this is just the forum to present a challenging idea and follow through with it. We are rogues in here bro

brandon429

 

[MiltonP]

Thanks. I am planning on holding out until July at the earliest to add the fish. I want to try a pair. The males I have watched seem alot happier with a female to flirt with. What do you think about dividing the tank for the refugium. It would be 12"x12" by whatever depth the majority recomends. I also need to learn the best way to plumb an ingernal refuge.

I have been studying Brandon's Picos for ideas. I could use one of the Azoo lamps on the end and dark acrylic for the divider.

 

[Minh Nguyen]

Mandarin is a very hardy fish, but does require live foos. A 20 gal tank, even with a small refugium, is not big enough to keep even one Mandarin. I am sure that your Mandarin will die of starvation unless you got one that eat prepared food. The chance of this happen is few and far in between. Mandarin are such beautiful creatures. It make me sad to think that most of the mandarin going through the LFS will be dead in a few months in small tank like what you plan. Please do not try.
Minh Nguyen

 

[bowser]

I've been thinking about doing the same kind of thing myself. Before anyone gets the wrong idea, I already have a mandarin in my 90, there is a refugium in this tank, plenty of copepods, etc... and if needed, I would have no problem moving the new mandarin into the big tank if necessary.

A couple of thoughts on your plans MiltonP~
The first is to try this with only one mandarin, see how it goes. If everything goes well, then you can try and add another. I would follow Brandons suggestion and wait awhile before adding the first, but then I'd wait another 4 months before adding the second one, to see how your pod population holds up with the first. BTW, no problems with 2 small fish in a 20g.
The second is to plan on feeding live brine to your fish as a supplement. You will need some sort of container for the shrimp, with an air pump w/line for circulation and gas exchange. You will also need to feed the shrimp, I feed mine DT's and SW vitamins. Since most live BS are sold in fairly large batches, you will probably also need to change the water in their container once a week. You can use a regular net to strain out the adult shrimp with. Or you can raise your own....
Even though you will need plenty of LR, don't forget to leave some open sand too as the pods will also crawl over the sand. As far as the refuge, I would use clear acrylic instead of the dark. It would look better, and make sure you have some holes drilled in it for circulation and so the small pods could get through. I would have the divider high enough so that any snails you might have in the main side won't be able to get to the refuge side. Pack the refuge with macros and some rocks too. If you have any hair alge, you might want to consider putting some in there too! Pods love it! Circulation can be a problem in there as you don't want anything that will chew up any floating/swimming pods, so either a powerhead with a pre-filter sponge, or even a small in-tank Fluval with filter floss in the container will work. Make sure you clean these regularly!
I would not have a skimmer on this system.
I've also been toying with the idea of training the mandarin to eat prepared foods. I have managed in the past to train a diamond goby who will now eat anything given, even flakes. He will rise up to the food like any other fish. Plus, I've trained my lionfish to eat "dead" foods, so I wonder if anyone has actually TRIED to train them?
Good luck with your endeavor and as Brandon has said, it would be a good idea to find the fish alternate housing (before you get him) so if the fish starts going downhill, you can get him out of there.
HTH

 

[Marrowbone]

...I could use one of the Azoo lamps on the end...

For lighting you might want to consider the Lights of America 65watt PC available at Home Depot. They fit on top of a 12" wide tank almost perfectly. Just set it on top and the plastic lens/cover sticks down inside (only a little too far). I've been putting them on my 30gal AGA sump/refugium and my 29gal tall AGA plant tank. They SAY they put out the equivalent of 500 watts of light, but even though it doesnt look like quite as much as 300+ watts of VHO, its still pretty dang good. For $30 plus a power cord and 65 watt consumption, I'm finding them to be pretty great.

 

[Anemone]

Yes, people have trained mandarins to take prepared food. It's not easy, and actually works much better in a smaller tank (such as is being suggested) where you can control the location of the added food. A process that has been explained to me:

First, get the mandarin eating live brine (pretty easy). Then, get it eating live brine from a turkey baster - basically train the mandarin not to be afraid of the TB (or airline tubing attached to the TB), and to recognize the TB as a source for those wonderful live brine shrimp. Next, mix in fozen enriched brine with the live brine in the TB. If you have worked it right, the mandarin will recognize the TB as a source of food, and gently pulsing the TB will provide some movement to the dead/frozen brine (which may be necessary intitially for the mandarin to accept the non-living brine). Eventually, the mandarin will accept the frozen brine without live brine mixed in.

As you can see, this regimen would be much easier in a smaller tank, especially one without any other fish to compete for the food. It also takes quite a bit of time every day to get a fish trained. If you're willing to take the time to train a mandarin to eat prepared foods, then I'd say a 20 gallon tank would be fine. If not, then I'd say a much larger tank would be necessary.

FWIW,

Kevin

 

[CAT]

I've been toying with this idea as well. My plan would be to use a 44 long and put a piece of eggcrate as a divider between the refugium section and the section where the mandarin is. Still thinking...

 

[brandon4291]

let me restate, if the mandarin quits eating or depletes his food supply too quickly (in spite of the special measures that will be taken) just remove him, trade him back to the LFS or put in a new tank (larger) then he will definately not die. Its not like a trial stay in a 20L will certianly be fatal! We are just testing how well the system will generate his food source.

I knew this would get some heat, but suprisingly there are some other optimists as well. Not that this will be easy, but I do feel its possible for an experienced aquarist.

JMO

b429[/list]

 

[MiltonP]

I will do as suggested and start with one Mandarin and see how it goes. One of the themes that has come up repeatedly is large copepod populations in the Nano, and Pico, aquariums. This should be obtainable if there is no competition for the food supply. I may test the reaction to the brine but the goal is to get to a balanced system for the dragonet(s).

I plan on at least 10" of open sandbed at one end. Will a 2"-3" bed be deep enough or should I go to 4"+? I don't want the refugium to be only zone agreeable to copepod production. A 30" 25 gallon might have been nice for more height to work with an even deeper bed but I believe this can work with a readily available tank.

I am also open to invert suggestions that complement the goal for a dragonet environment. No stress builders welcome.

PS - Those of you who haven't checked out the Nano section should see what they are accomplishing. Love your work, Brandon

 

[brandon4291]

Hey thanks MiltonP--I wish you the best of luck as well on your mandarin tank. IMO mandarins/dragonets are the most beautiful marine fish out of them all. Nothing beats the psychedelic coloration//// It will be a challenge though!!!

The only reason my posts to this thread have that tone (somewhat sarcastic) is because I think its okay to design a special-application system and give it a try, as long as you have alternatives for the animals should it not work out. Thats kind of what I did in a few experimental reef aquariums--I promised if the corals stayed retracted or showed signs of stress I would remove them... they don't, so I didnt!

it does go against public opinion to keep a dragonet in this small of a tank, and anyone who disagrees with the idea is definately thinking of safety for the dragonet(s). But, the challenge to design a massively-productive refugium will make it a fun endeavor, and you can always change it to a different fish if you need to. thats all I am meaning...
I know you'll take care of things if he/they dont feed well or if your copes thin out.

BTW, how much are those starter cultures you can buy to seed sand beds? Maybe your refugium will work great and you might have to re-seed every few months, as that may be part of your new maintenance regimen on a 20L dragonet tank.

just tossing out ideas...
b

 

[MiltonP]

Your previous responses didn't bother me a bit. The success you and others are having with Nano natural reefs and the moves elsewhere to DSBs with no additional filtration has me thinking that the problems with dragonets needs revisiting. I believe any specimens I get will be better off than those in most LFS's from what I have seen. The tank bed and refugium size, bed, & contents will be the hardest decisions.

It was either that or testing hard corals in low lighting environments. I believe the trend to higher wattage lighting was due to unnatural systems that filtered out nutrients the corals need. MH lighting offset this by putting the photosynthesis in overdrive. MH lighting doesn't match anything I ever saw in my years of diving.

 

[tazdevil]

Miltonp, another suggestion:
Try to acheive water flow without using centrifugle pumps (most current one's are); they're great at producing water flow, however, they're also great at shredding copepods. I have no idea how this could be done, but I have heard of it being done. In my sump, I did notice that after I placed my skimmer on a platform supported by three-way short pvc "t's" that they were hiding and breeding in the t's! Saw hundreds swimming around at night, hiding in the pvc t's.

 

[MiltonP]

My LFS pointed out that the more expensive refugium complete w/light fixture had the pump on the output side instead of on the input side. He pointed out that the CPR units had the pump on the input side and were a much safer bet. I have seen foam input filters for powerheads but I question there usefulness.

You got me thinking that some small capped pcv elbows in the refuge might work as ready-filled copepod scoops if the population in the tank needs a boost.

 

[bowser]

The sponge pre-filter will do the same thing....the copepods will congregate there for easy capture should the need arise. You shouldn't be doing that too much as you don't want to deplete your breeding population.
What I had in mind (for me to do) was to section off about 1/4 of the tank for the refuge, the entire tank would have 3 to 4 inches of sand so that other critters will have a place to breed too. Mandarins not only eat the various pods, but also worms, even small bristleworms, and I am wondering if they might also eat other things like the tiny brittlestars. I know the one I have in my big tank eats these unidentified creatures that resemble medusa's (but aren't), so any bonus animals you can provide will only help your fish.
I would also provide "pathways" for the various critters to get out of the refuge safely. Instead of using acrylic, I was going to go with one of those plastic tank dividers. They have hundreds of tiny holes so that the adult pods (such as amphipods) would not be able to leave the refuge. I would modify this by cutting 2 very narrow strips, not only at sand level, but also underneath the sand so the sandbed fauna can move back and forth.
I would also put LR next to the pathways so that the pods would have easy access to the main tank, and may even find safety in the tightly packed rock. Any extra breeding colonies is a plus! Macros on the main side too! Only inverts that I would include would be some mushrooms, maybe button polyps. A few snails like astreas.

Thanks for the tip Anemone! That feeding trick sounds like it would work too!

It's refreshing to see the attitude here. If you were to post this at RC, there would be a good chance of getting flamed for even thinking about this! As long as everyone understands that no one wants to hurt the fish involved but that this is strictly an experiment that if it were appear to be failing the fish would be removed to another bigger tank. I love mandarins too, one thing I hate to see is when someone posts that theirs is starving to death. I would rather be able to offer a way to train the fish, or provide a constant food source even in a small tank, rather than sit there and know that one is dying and you can't do anything to help it.

 

[MiltonP]

Thanks Bowser, I had been leaning towards the larger internal refugium, but hadn't considered the perforated divider. What are your ideas regarding water flow/powerhead size/placements in this set up?

I am also curious about your opinion of a skimmer in this set-up. I believe the skimmer would likely be taking away some of the nutrients needed for the copepods' food supply. The Pico tank folks remove cuttings of Macro-algae as an alternative to waste removal via skimming.

Lastly, I am still considering using a 29 instead of the 20L, however, I am not a big fan of tall/show tanks. comments? If I was choosing on dimensions alone, I'ld go with a 40 breeder, but I want to achieve a set-up that is reasonable to duplicate for those who want to keep a dragonet 'happy' and have space limitations.

 

[Anonymous]

fwiw-

while i am a wee bit leery of recommending a mandarin in that small a pod raising set up, i will also say that many mandarins will readily take to eating frozen bloodworms, which, when soaked in selcon, can be used as a 'training food' for flake.

we kept many(actually-about 90% ate the fr.blood.s) mandarins that way at the lfs, and it seemed to keep them doing well, at least for the time they were in the store.

frozen ocean plankton and gammarids would also be an excellent thing to try, or even sliver shavings of frozen fish and shrimp.

 

[MiltonP]

I talked some more with the LFS that specializes in Reefs. We came up with dividing the tank with two sheets of acrylic drilled with 1/4"+ holes for good water flow with finer mesh or net sandwiched between the sheets. How fine the mesh should be is the question. The goal being to keep the copepod breeders in and let the little ones through.

I also studied the behavior of the dragonets residing in their level 4 coral display. The corals are on various levels of eggcrate suspended over the sandbed. The dragonets spent significant time between the bed and the first level. I plan on suspending the rock on a drilled pvc grid. More sand bed and rock exposed that way.

 

[bowser]

That's a good idea to suspend the rockwork on eggcrate! I didn't think of that!
Powerheads will have to be stronger than what you would normally have in a tank that size because the sponge filter will slow the flow rate down. I would certainly have at least one powerhead on each end. I was thinking on this more and it would seem to me that to keep things circulating properly, you will have to either keep the divider just under the water line, or put notches in the top. That way, the powerhead on the main side could be aimed towards the top of the divider and the one inside the refuge could be aimed towards the holes in the middle or bottom of the divider. Still thinking about what gph you would need for this, and then there is the problem of mechanical filtration. I really like having a filter that I can pop some carbon in if needed. And the extra water flow would be good too. Not sure how well a small filter will work if you have to put a sponge on it????
Your divider idea sounds interesting, and it would work just fine if you can find something small enough to do the trick. Can't think of anything offhand....window screen would be too big.....

Vitz~ that's good to know about the bloodworms, I had wanted to try them with the mandarin in my 90 but I couldn't figure out how to get them to her as the other fish are quite greedy! I don't really mind over feeding live brine, after all they are alive and will stay that way until they're eaten, but bloodworms are a different story. I am concerned about some being swept under some rocks and decaying.....
Now I know that the bloodworms are a good choice to start with. I figured that I would start with live ones then graduate to frozen.
I also want to try shredded squid as that is the food that triggered the feeding response in the diamond goby.

I wouldn't use a skimmer, but then I don't use a skimmer on either one of my salt tanks. (I have the 90 and a 20L)
For me, I would use a 20L but only because I have one laying around! Really though, a 29 would be fine too!

I would try this training/small tank with the mandarin I already have, but the thought of getting her out of there is too much to deal with... (((shudder))) nah, I'm just gonna try this with a nice male.

 

[CAT]

Interesting discussion

One problem I see with the fine screening is that it would get gummed up pretty quickly and need a fair amount of cleaning. This is why I was thinking of the eggcrate as a divider.

Another idea I've seen is people using eggcrate 'boxes' with rocks inside at the back of their tanks. Sort of an in-tank refugium that keeps the predators out of the breeding area. Several of those could be used as bases to aquascape the rock.

One question - do the mandarins hunt at night? This is when I see most of the pods cruising around my refugium.