Long Trip, Impossible?

[frost147]

I'm a Merchant Mariner. My job entails going to sea for 2 months at a time. I'd really like to own an aquarium again, but I realize this is probably going to have to wait until I live with someone who can take care of a tank while I'm away.

However, I've read about 100% self sustaining aquariums/ sealed systems before and it makes me curious if it just might be possible to have a setup that can sustain itself for 2 months.

I was thinking along the lines of a 29 or maybe even a 55 gallon tank, planted, with a single male betta or a half dozen of some type of small schooling fish. I could possibly talk a friend into feeding them once a week (or reloading an automatic feeder), but I'm not going to ask them to do water changes, etc.

Obviously, the showcase of the tank would be the plants (and a really cool piece of wood I never threw out from my last tank), but also I've always liked the idea of 'rescuing' one of those poor bettas they keep in those little plastic cups in the pet stores.

Is there some kind of critter that can live in the tank while also serving as dinner for my fish? Is two months just flat-out too long to go without a water change whatsoever?

Impossible?

 

[jsoong]

Welcome to AA!!

I wouldn't say it is impossible, but it will be challenging ....

You would need to have a fully balanced eco-system to have a self-sustaining closed system. A heavily planted tank with low bio-load may be a possibility. You might try the Dutch method or perhaps an all natural method like Dianna Walstad's. In theory, if you get it balanced just right, you can go Dutch without a filter, fertilizer, or any water change. I don't quite have the experience to do that or to give advice on how to go about getting the perfect balance.

In theory, you can also skip the feeding. My Hillies lives off the biofilm (various microscopic critters that lives in the tank) and never eat any propared food. He is fine for well over 3 years without feeding (from me). Various algae eaters may also be OK in a tank that is actually growing algae. <Of course you want to grow just enough algae for the fish, but not so much that it takes over & be a mess ... again a difficult balancing act ... most people will feed the algae eaters.>

Establishing a closed eco-system is demanding. I don't know if anyone here is doing it & have more hands-on advice.

 

[BigJim]

It's possible, but I don't think you'd like it. When I was away at college, my 29g tank got neglected and basically turned into a pond-like environment.

All I had in there was a raphael cat and some guppies my brother threw in. The tank turned green with alge, the guppies ate the algae, and the catfish ate the guppies. My mom said she'd throw food in, but I doubt it was more than once every two weeks.

Half the water would evaporate when I was gone. The filter started making noise when the water got low, so someone unplugged it. I'd come home every 1-2 months and fill the tank back up. I went with the "If it ain't broke, don't fix it" theory and didn't change any water or clean the tank. The tank ran like that for 5 years.

I don't see it possible without a ton of green algae and a repopulating group of feeders. I did get some early morning sun and late afternoon sun on the tank. I have no idea how what the water parameters were. The algae probably helped absorb some nitrates, but I can't imagine the parameters were good. I still have that raphael and he's a tough little monster. He's at least 15 years old.

I told my story to show that it's possible to have a self-sustaining aquarium, but I wouldn't recommend attempting it. I got lucky with my tank reaching the right equilibrium. People would look at the tank and ask "Are there actually fish in there?".

There are sealed systems, I think they're called biospheres, but I've never seen any with fish. Usually they have shrimp of some kind.

Is there room to take a small tank on the ship? My wife has a 5g Eclipse hex tank that could work. It's got a small footprint and the filter and light are incorporated into the hood. One power outlet and a three-way splitter (light, filter, heater) are all you'd need.

 

[frost147]

Thanks for the advice.

Jsoong:
I hadn't heard of Diana Walstad before, but her ideas for a tank are pretty much exactly what I had in mind. I'm definitely going to pick up her book when I get the chance.

BigJim:
I like hearing from somebody who had the exact same situation I would be in. I had completely forgotten about the evaporation *slaps forehead*. I definitely don't want a half-empty mess that everyone calls ugly. It's definitely something to consider. The tank-bug hasn't outweighed my logic center yet, but it's getting a little dicey.

 

[jsoong]

Evaporation isn't too bad a problem if you have the aquarium enclosed with a glass top, and there is always the option of an auto water top up system.

The challenge is going to be finding that perfect balance with the eco system.