The Final Water Change

[mark1980]

When I have cycling my tank and I have ammonia and nitrates tests of 0. What percentage of the water should I change before adding fish. Another question I have is would it be ok to take my filter out and fill the tank with water from the hose and then de chlorinate it in the tank before replacing the filter or would it be better to dechlorinate it before it goes into the tank. (this would take a lot longer as I would have to dechlorinate it in a bucket one by one)

 

[Chubbywubs]

if the levels are perfect, why would you want to change it at all?

 

[mark1980]

Because the nitrates will be sky high. I am right in thinking that you have to do a water change between completing the cycle and adding fish aren't I?

 

[vinylman]

When I have cycling my tank and I have ammonia and nitrates tests of 0. What percentage of the water should I change before adding fish. Another question I have is would it be ok to take my filter out and fill the tank with water from the hose and then de chlorinate it in the tank before replacing the filter or would it be better to dechlorinate it before it goes into the tank. (this would take a lot longer as I would have to dechlorinate it in a bucket one by one)

Do you mean Ammonia and NitrItes?. You should always have some NitrAtes in your tank water. If you mean the cycle has finished and Ammonia and Nitrites are 0, then you should do a VERY large water change of 80/90%.

 

[mark1980]

Sorry, I meant ammonia and nitrites. 80-90% water change is the answer I was looking for. Thanks

 

[Chubbywubs]

Ok cool thank you. Id guess i missed the part about the water change, i just thought if there water levels were perfect you could just plop your fish in...



Good thing im not buying the tank yet

 

[treelo]

if your ammonia and nitrites are reading at 0 then its time to put your fish in, the cycle is complete

from what i have gathered, nitrates isnt harmful at all, and will start to drop when you add real plants(which feed off the nitrate)

 

[Rooster]

You are ok changing all of it ! Or at least half to be on the safe side...

 

[Chubbywubs]

sorry to post hijack, but if the water is perfect and ammonia free, why would any one want to change it?

 

[treelo]

sorry to post hijack, but if the water is perfect and ammonia free, why would any one want to change it?

exactly

 

[vinylman]

It's all in the 'fishless cycling' guide.

 

[doresy]

While cycling you are adding a continual source of ammonia which goes on to produce nitrIte. When bacterias form in sufficient quantity these are nutrified to a level of zero. The by product of this action is nitrAte. This IS harmful to fish but only in large quantities so needs to be diluted after cycle has been achieved, just before adding fish (and when temp has been leveled)

Adding the ammonia in a fishless cycle is just immitating fish and old food 'doing its thing' so you don't wait for ammonia and nitrIte to rise before doing a water change when you have fish do you? So that's why you do a water change before adding fish even though your levels are 'good'

 

[Chubbywubs]

No of course not, but when you add the ammonia, and your filter media develope and the level are all safe and perfect, what would be the point in disrupting this by changing the water and having to get the levels back down? The water is perfect once the cycle is finished, and i still dont understand why i would want to change it.

All you said was that the ammonia and nitrite levels will rise, but they will rise, but they wont until you add fish or do the water change, as your not adding anything more in as the cycle is finished.



Just confusing.

 

[Miss Wiggle]

because when your cycle is complete you'll have a nitrate reading of probably 80ppm+ this is way too high for fish so you do a big water change which gets rid of the nitrate.

remember it's the filter you cycle not the water, the bacteria does not live in the water, the levels are all affected by the filter. once you have the filter cycled then putting new water in will do nothing to affect the cycle, you'll still be able to process any ammonia.

think of it like this, when the tank is running normally you should do water changes every week to keep nitrate at a manageable level for an avergaely stocked tank 30% a week is sufficient, with fishless cycling you simulate running the tank with a very heavy fish load and then no water changes for a couple of weeks, so you do a sort of 'catch up' big water change to get the nitrate down before adding fish.

No of course not, but when you add the ammonia, and your filter media develope and the level are all safe and perfect, what would be the point in disrupting this by changing the water and having to get the levels back down? The water is perfect once the cycle is finished, and i still dont understand why i would want to change it.

All you said was that the ammonia and nitrite levels will rise, but they will rise, but they wont until you add fish or do the water change, as your not adding anything more in as the cycle is finished.

the above is the issue, that staement is not correct, after cycling you are free from ammonia and nitrite but have a significant build up of nitrate to be removed

 

[andywg]

No of course not, but when you add the ammonia, and your filter media develope and the level are all safe and perfect, what would be the point in disrupting this by changing the water and having to get the levels back down? The water is perfect once the cycle is finished, and i still dont understand why i would want to change it.

All you said was that the ammonia and nitrite levels will rise, but they will rise, but they wont until you add fish or do the water change, as your not adding anything more in as the cycle is finished.



Just confusing.

Look again at what is happening.

The cycle process means there is a sufficient bacteria colony on the filter media to process ammonia and nitrite at the rate which it will be produced by your future stock. The end result of this process is nitrates. During the cycling process one will probably add a fair amount of ammonia, meaning you are left with a somewhat elevated nitrate level.

In order to start from cleaner water you remove a lot of the water containing nitrates and replace it with fresh water. This will do nothing to the bacteria colony or the ammonia and nitrite levels as the bacteria are in the media, not in the water.

Water at the end of a cycle is far from perfect, it is high in nitrates. The easiest and best way to get rid of nitrates is through water changes, hence the water change at the end of cycling.