Self Cleaning Fishtank?

[martypants16]

Hi all,
Question for you....... Can a well established tank ever get to the stage of self cleaning and hence not requiring any water changes?
Reason i ask is that a guy in our local aquatic centre claims his tank has been established for a few years and he no longer needs to change the water. Also, other people i have spoken to, that i consider less well informed ( well you can pick up a lot of info on here !!! ) claim that they never perform water changes either with no ill effect..........
Personally i am extremely sceptical and wondered what other folks thought about this....

 

[Mikaila31]

I would have to say no, water changes help keep the water chemisty stable and they will remove toxins that would slowly build up over time.

 

[Ivan Sloshed]

accordig to the books you should partial change the water at lease once a month i like to do mine approx every 7-10 days i dont like to see all the poo building up as for never cleaning, where would the poo go. Ivan

 

[karlp]

Some natural planted tank afficienados do go with very infrequent water changes and it works because they setup a carefully balanced eco-system with low fish stocking levels and lots of plants. The plants take up the fish waste and the minerals in the tank are replenished through the fish food.

However, most that claim that they don't need to do water changes are just lazy and risk high levels of nitrates, phosphates and bacteria in the tanks which could cause health problems for the fish long term and cause algae blooms.