Closed ecosystem tank

[rivoth]

Hello New Mexico Ocean Keepers,

I've been thinking about starting a saltwater reef tank for a long time, and I'm just about ready to take the plunge. My tank goals seem to be a little different than what most people go for, so I thought I'd run them past other local tank keepers for their ideas and input.

I'd like my system to be as self sufficient as I can reasonably make it. Lights, current generation, and temperature control are required. For filtration I want to rely on a deep live sand bed and live rock. There will be no skimmer or external sump. Bio load will be kept light and built up slowly over time as I learn how much my setup can handle.

After initial cycling of the sand bed and live rock I want to start by essentially making the tank into a healthy, diverse refugium. Once this part of the system is well established I will start adding critters that can live off of, but not overgraze the algal and pod growth. I want to find out what types of invertebrates can coexist peacefully in this type of setup. Anything that requires regular outside feedings should be avoided. I'd also like to make my sand bed have a diverse spectrum of life as well.

I've read enough to be fairly certain that this type of a tank can be done, but not nearly enough about the specifics of what to populate it with. Any ideas on how to make this tank work, and how to populate it are appreciated.

So far my purchases have been limited to a RODI unit designed for both home drinking water filtration, and DI for reef keeping water filtration. I've got a very solid old oak desk to use for a stand which could carry up to a 4' x 3' tank. I'm thinking more along the lines of a 36"x18"x24" tall aquarium which would give me about 67 gallons. I need some height since I want a 6" deep live sand bed.

Those are my thoughts so far, hope to start getting to know all of you.

Frank

 

[Kep]

To support life off of pods alone you are going to need a lot of breeding space.

Set up a bunch of chaetomorpha and buy a bunch of pods once it's cycled. Make sure that this is a stable system in and of itself, which I would guess would take a few months at least.

Even then, I would really be afraid that keeping even a single fish such as a small mandarin or a sixline wrasse would completely demolish the pod population if put in the same space. (no refugium)

You certainly have a much better shot at a closed system if you do not include fish. All they do is eat and poop. A full coral system could definitely support your goals. You will still need to add calcium and alk supplements and monitor all the same parameters that everyone else does.

Let us know if you attempt this!

 

[rivoth]

Thank you for the feedback Kep. While I had hoped that a 65 gallon tank might be able to supply enough pods to supply at least one fish, it is not critical to my plans.

Could at least one herbivore be fed without destroying the microalgae population? It would make it easier to keep an area clear for coral with a helper. Plus I'll have an import/export imbalance if I'm removing algae from the tank without adding anything in it's place.

Having corals is much more important to me than fish. I'd also like to grow Ulva, and Graciliaria microalgae along with the chateomorpha if that is feasible.

Once the tank has stabalized I'm hoping that there will be some Albuquerque tank keepers with well populated live sand that can get my sandbed started with the different types of sandbed life beyond the bacterial colonies.

I also need to learn how well Urchins, crabs, snails, starfish, and all the rest will fit into the system.

I understand it can take a year or more, but at some point the sandbed should be able to support some marine plants which would add to the diversity, and help with recycling the detritus in the sand.

Thanks again for the feedback,
Frank

 

[El Jefe9830]

I don' t know anything about this. Sounds like it could be really fun, and have some great potential. I still think you will have to do water changes, and the such, but maybe I am way off base with that thinking.

I look forward to seeing how it goes for you, should you choose to accept your mission.

 

[rivoth]

I've decided to proceed with my plan. This weekend I added about 4" of sand, 50 pounds of live rock, and a cocktail shrimp. I want a 6" deep fine sandbed for later addition of marine plants, so I'm waiting on more sand before I do my aquascaping.

The water was really murky from the sand, but after two days it is all clear despite strong circulation. My rock now has a dusting of fine silt that I need to siphon off. Ammonia levels are rising and so are Nitrites. No measureable Nitrates but my resolution on the Nitrate test is only 10 ppm so I think I'll need a better Nitrate tester.

After ammonia levels drop down I need to figure out how to get my sandbed colonized. Maybe there are some club members with established sandbeds full of life who can help. I also need to find sources for Macro algae.

Regarding some of the other points, I'm still planning on water changes and supplementing the water chemistry as necessary.

I've been reading that corals also feed off of the pod population. That will limit how many of them I can keep. It's going to be a challenge trying to find a healthy balance with lots of diversity.

 

[El Jefe9830]

Nice man. Keep us posted. I would love to see and hear how things go with this.