After cycling is completed , change a part of the water before adding fish or not ???

[minajaguar]

After cycling is completed , change a part of the water before adding fish or not ???
And after how long can i add fishes just the day i found NH3 , NO2 = 0 ,, "add immediately or wait some days"

[BCreefmaker]

What are you NO3 levels?
If you have no ammonia, nitrite, or nitrate (NO3) then you are good to add fish and a few snails or crabs if you like. No water change is necessary, but you can start a 10-15% water change per week routine now if you like.

[MrTuskfish]

I would wait until your new fish, and every new fish, spend 6 weeks in a QT.

[dunc101]

Originally Posted by MrTuskfish

I would wait until your new fish, and every new fish, spend 6 weeks in a QT.

+1 to what MrTuskfish said. Remember that the bacteria resides on your rock, therefore, you could do a 100% water change if you really wanted to without affecting the biological filter. The main goal is to get your nitrates below 20, then add a part of your clean up crew (do not add them all at once because you likely do not have enough algae to sustain a full clean up crew just yet).

At this time, I would also start a QT if you have not already and place all fish in here for 6 - 10 weeks to observe for any parasites and/or disease. Unfortunately, we cannot treat sick fish in the DT which is why many use a QT. If it is not cycled, you can take a sponge from your DT (since it is cycled) and place it in your QT. Just use a simple HOB filter, a powerhead and / or a bubbler (4 bucks at walmart) and place a few pvc pieces for the fish to hide in for the QT. You will probably also want to buy a seachem ammonia alert badge for the QT just to make sure no ammonia arises while the fish is in QT. This can be as simple as a 10 gallon or 20 long.