Does anybody keep an aquarium like Diana Walstad?

[henry2703]

The fish may survive a year but that proves little, sounds extremely unhealthy to me your friend is only lazy, and there is no way a caring fishkeeper can not have a filter

its really hard to say... IMHO...

if the ecological system in the tank is fully balance, which may be in thsi case, you may start to wonder... is there a need to change water???/

Assuming that all waste broken down.... ammonia broken into nitrate and plants takes in all the nitrate......

The plant is give out sufficient oxygen for the fishes... and all...

I mean.. we live in this world... nobody needs to periodically change the AIR right?

Plus i always think that animal live on instinct.... oif the water condition is not right, there is not enough food, etc..etc.... they won't breed... the fact that her guppies bred twice or trice.... i think it is good....

Do i make sense?

 

[funkybodal]

As bignose said, you would defo. have to have some sort of surface disturbance. In the day time in a heavily planted tank, the plants would probably produce adequate oxygen during photosynthesis BUT at night when they stop, the poor fish could be pretty much screwed...

I guess you could solve this by turning on a powerhead/airpump at night.

Cheers,
Luke.

 

[Bignose]

Tempest, you are exactly right, aquatic plants much more prefer to use ammonia. In fact, after taking up nitrates, many of the aquatic plants have to expend energy to turn the nitrate and nitrite back into useable ammonia. Terrestrial plants are much better users of nitrate, which is why it is in many fertilizers.

Assuming that all waste broken down.... ammonia broken into nitrate and plants takes in all the nitrate......

henry, this is not right at all. The plants take up ammonia, the ammonia is not broken down.

 

[Ed4567]

To me this sounds rather similar to the use of live rock within a marine aquarium; to try to replicate the natural carbon, nitrogen etc. cycles as closely as possible. It is clear this methodology has allowed vast increases in the organisms that can be kept within marine tanks and a huge decrease in dissolved organic compounds within a tank.

I suspect that the plants are cut back regularly as a form of nutrient export to counteract the input of nutrients in food?

As a side note I'm sure that if you put this idea to people on the marine forum they would find it far easier to accept than people on here.

 

[mellowserra]

if the ecological system in the tank is fully balance, which may be in thsi case, you may start to wonder... is there a need to change water???/

I would like to point out that although there may exist a perfect ecological balance which keeps all of the tank parameters in check, who is to say that there cannot be a buildup of other things such as heavy metals or other contaminants in tap water, which would only become more concentrated as tank water evaporates and more tap is added.

I think that the overall ideal makes a lot of sense as far as plants go, but if there is stuff building up in the water I think it could adversely affect osmotic/metabolic functions and impede breeding stock in certain fishes.

Knowing very little of Walstead, I myself have a heavily planted 4ft tank set up using clay/laterite + peat/soil/vermiculite + sand, the fish seem to love it and my plants are thriving, growing faster than I thought they could (how many plants grow naturally in a bed of sand or gravel?). But I wouldn't dare not run my filters