Water changes Concern

[christian1971]

I understand that the water needs to cycle completely before adding fish. Why doesn't the water being used for water changes have to be cycled? Especially if you are doing a 50% daily change.

[Skip]

the bacteria are living in the filters.. thats what you want to build up or to be cycled.... wc just takes out old water and adds good, new clean water..

[Keith Perkins]

That's why if you're starting off new and buying from a breeder that will also sell you a cycled sponge you can start right up.

[christian1971]

Those bacteria in the filter must work very fast! Otherwise I would think the water change would be terrible for the fish.

[Skip]

if you change out the bad/waste water.. it takes bioload off the filters..

[X_factor]

When you first set up the tank, you cycle the tank, not the water. The cycling process is the process of building up beneficial bacteria (largely in the biological filter) so that the bacteria can convert ammonia into nitrite and then another type of bacteria converts nitrite into nitrate. Then you can get rid of the nitrate through water changes and plants will absorb nitrate as nutrition.

[strawberryblonde]

The water change actually removes built up nitrates so it's a good thing. It leaves you back at "zero" as far as fish and/or detritus pollution in the tank. Then, as the fish and the fish foods start adding waste, the bacteria in the bio filters eat it up and spit out a changed toxin. Ammonia gets changed to nitrites, then the next bacteria picks that up and turns it into nitrates. And then the next WC removes that...and on and on. =)

[ericatdallas]

The bacteria will also be on your tank walls and any other surface you have in the tank. The water does contain bacteria, but a majority of the nitryfying bacteria is on surfaces.

If you had "cycled" water you have "dirty" water. It makes more sense to put clean water that doesn't have ammonia or nitrates :)