As was suggested your tank is way to small for 5 goldfish. It is barely big enough for one. You probably have an ammonia and nitrate problem. Change 50% of your water and see about a bigger tank or trade some of the goldfish back if you can. [ Like 4 of them }.
As far as them being skittish...it could be the water or did someone make a loud noise near them? Drop something in the tank? With poor water i would expect them to be gasping for air at the top verses being scared. Though i imagine ammonia poisoning can change their personalities drastically.
Continue to do 50% water changes every other day or daily until you fix your problem. Even if they are very small fish now they still produce a lot of ammonia and will get big fast. Good luck.
__________________
100 Gal: Community.
55 Gal Hex: 2 albino socolofi; 2 labs
70 Gal: 1 bubble eye; 2 moors
29 gal; 5 Aphyosemion Australe, 5 Iriatherina Werneri, 4 dwarf Praecox, kuhli loaches, panda cories, clown pleco
65 gal; 4 angels; platy/swordtails, cories, chocolate albino pleco
60 gal. Chocolate oranda, Black Ranchu, Pearlscale, Lionhead.
40 gal. 3 calico oranda babies.
Two 6 gal betta tanks
10 gal ADF
Disasters are
just another star
falling in my yard
Red Hot Chili Peppers |