What is a large water change?

I am doing a fishless cycle, and it is finally moving along. Right now, ammonia is at 0 ppm, nitrites are at 0.25 ppm, and nitrates are at 10 ppm. My next step is to wait until both ammonia and nitrites are below 0.20 ppm and then add a bit of ammonia, and see if the tank can convert that.

After that, and before adding fish, is says to do a large water change, but how much is "large"? 50%, 75%?

 

I consider 50 average and 75 pretty big

 

I consider 50 average and 75 pretty big

Thanks so much! Very helpful.

 

I usually consider 40-50% change normal, anything smaller i refer to as a small water change, anything bigger i usually refer to as big or large water change.

 

Once the cycle is complete you want to change enough water to lower the nitrates to 20 or less. If the nitrates are 40 a 50% water change will get them down to 20.

I would go ahead and get the ammonia back up now that is is 0 and nitrites are this low.

 

I usually consider 40-50% change normal, anything smaller i refer to as a small water change, anything bigger i usually refer to as big or large water change.

So, is my goal then to remove as much nitrate from the water before adding the fish?

Once the cycle is complete you want to change enough water to lower the nitrates to 20 or less. If the nitrates are 40 a 50% water change will get them down to 20.

I would go ahead and get the ammonia back up now that is is 0 and nitrites are this low.

Okay. That makes sense. I'll go ahead and add the ammonia today, then. So, as a rule, after I add fish, I should strive for 20 or under nitrates?

 

So, is my goal then to remove as much nitrate from the water before adding the fish?

Okay. That makes sense. I'll go ahead and add the ammonia today, then. So, as a rule, after I add fish, I should strive for 20 or under nitrates?

That is a good safe level for nitrates.

 

That is a good

That is a good safe level for nitrates.

You have been so helpful! Thanks so much.