Self-sustaining Ecosystem in a planted tank?

[kreuztraeger]

Can a planted tank manage its own pH levels, and in theory, run indefinitely without intervention in the form of water changes?

Here's the thing. I have one common goldfish, only about 2.5" including the fins, in a 10 gallon. I don't know if that's enough to keep the nitrates high enough for the plants or not. Anyways, I have done a little moving with the resident amazon swordplant and one fully bloomed aponogeton plant (2 others starting to grow) but I wonder ...

Is it normal for the appearance of the leaves to fade slightly after a water change? I have recently been very careful about the pH of my fishtanks, due to an acidosis episode that occured about a month ago, so there have been several water changes, one or two a week.

 

[sumthin fishy]

No tank can be self sustained. If it's not water changes you are doing, it will be adding so much junk to your water it would be easier to just do the water change.

Keep in mind in nature there are waterchanges constantly taking place in one form or another.

Also the goldfish in a 10 gallon will not last too long. It will definatly outgrow the tank, and have severe health issues from stunting.

 

[fballguy]

A tank will never be self sustaining. You have to do water changes to remove waste, which will be very abundant with a goldfish.

You want to know what stunting does to a fish? Check this out.

 

[carttman]

Also the goldfish in a 10 gallon will not last too long. It will definatly outgrow the tank, and have severe health issues from stunting.

I would have to second this because I have seen it done. I won a goldfish at a fair one time and I was constantly buying bigger fish bowls and aquarium's for him to thrive in. Finally I had to give him away to a local fish dealer that has huge ponds for goldfish to live in. It is really amazing how big they can get.