Which fish to add first?

[Katy]

So, the new tank is cycling, and the fish are still in quarantine for another month, but I see two opposing views on what order to add fish to the newly cycled tank (when the time comes): Loaches first as they are territorial, or dither fish first to further cycle the tank.

At this point our only other fish are 3 cardinal tetras and a pleco.

[Diana]

If you are doing the fishless cyle this grows so much nitrifying bacteria that you will be able to add all the fish at one time.
If you add less than a full load the beneficial bacteria will die off to handle just the amount of waste from the fish you add. When you later add more fish the tank will have to go through a mini cycle to re-grow more bacteria.

[Katy]

Good!

I think they are going to love their new home

And the fishless cycle is now eating up more than 3 tablespoons of ammonia a day -- think that should cover the fish we are adding (although, if they keep growning as fast as they are now

[Diana]

That is a lot more ammonia than the fish will contribute! So your tank will have a really good population of nitrifying bacteria
You might point this out to the people that are suggesting stocking the tank slowly. Print out the fishless cycle and show them how easy and productive it is.