[Ponds-Koi] Fish, Fish, All Kinds of Fish
That was me! (that told you your fish likely spawned and had snacks resulting in the foam) 
Could that striped fish have been a tadpole?
Did you buy any plants? You could have gotten some fry in with your plants.. It sounds like a Zebra Danio from your description and they are cool/cold water fish (like goldfish) so maybe your plant supplier had them in the same pond that they kept their plants.
You won’t be able to keep all them goldfish in your 250G pond so any that survive should be rehomed unless you’re prepared to enlarge your pond or do very frequent PWC’s… like daily… as the fish grow.
Lenny Vasbinder Fish Blog - http://GoldLenny.blogspot.com
Category: Philippines Internet Koi Society
