Should I do a water change for my first fish or is it okay?

[astral_ocean]

My tank is now cycled and I have dozed 0.5 ppm of ammonia to make sure it can convert everything properly before I go in to buying my first fish; which thanks to the thread I made the other day and those that helped me on there, the first fish will be a Fire goby.

I tested everything, ammonia got down to 0, nitrites finally got down to 0, and my nitrates are 40. Are the 40 nitrates good for fish only (for now) or should I do a water change before getting the fish. It’s a 45 gallon tank with a 10 gallon sump, there’s probably a total of 45 gallons of water in the system as a whole.

If I should do a water change, how much should I do?

 

[Mr. Mojo Rising]

I would do approx 10% water change. 40 nitrates is about the max of what a fish will be comfortable in

 

[elorablue]

Just for reference at the end of my cycle my nitrates were 60ppm ish. I did a 60% water change and added my first pair of fish a couple days later. Worked well.

edit. It will never be easier to do a massive water change than it is at this stage with no inhabitants

 

[Just a Wrasse.]

I'd say 20% water change.

 

[ReefGeezer]

Double your current nitrate level would not hurt the fish. Nitrates will rise for a while though as you stock your tank while the system matures enough to process nitrate to nitrogen gas effectively. The worry is not the fish. Limiting nitrate is more important to help prevent pest algae and to manage all the other pests that will pop up in the "ugly" period. FWIW, I do 30% at the end of a fishless cycle just to give the water parameters a boost before I add fish. That would drop nitrates to about 20-25 ppm in you case.