Beware, Mark, be very aware. I see an enabler post below, and gasp by my
beloved K30 no less!! ;-)

I'd add a few more at a time now.
Would be fun to go to the pet store for the kids
and pick out some really pretty ones.

Be strong Mark, stick to your guns, let the pond balance.

K30 does reinstate herself into the RP Hall of Fame by suggesting a Q-tank
below:

You might consider setting up a quarantine tank.
I've never done it, but if your kids are really fond of
the first residents it would be a way to safeguard
them against any illness the newbies might bring
in.

The old "do as I say, not as I do," above isn't very convincing though.s

Keep your stocking level low

Read: Don't buy anymore they will make more.

and feeding level spare

Or not at all even better.

and you'll hopefully avoid any really bad green water
problems, especially if you've gotten carried away with
plants which it sounds like you have! :-)

After that post, if she was Catholic I'd make her do a few Hail Marys in
front of the Virgin Goldfish, but she's not, I can't, and there no such
thing as a Virgin Goldfish. ;-) ~ jan

~Power to the Porg, Flow On!~