Sophie

A couple of things, and I hope you aren't too shocked about these:


1) You are massively overstocked. Your tank is roughly 14 gallons.
Goldfish require approx 10 gallons each. If you do have a comet, he can get very
long!

2) You should be testing the water quality with an ammonia, nitrite and
nitrate tester (and a ph tester too) - probably why your minnow died.
This will ultimately show you if your water changes are enough (I suspect not)


3) I'd suggest getting a gravel vac and vacumming the gravel to keep it clean
rather than removing the fish.

4) Snails do not keep tanks clean. Yes they will eat decaying food/plant (which
is a good thing)
but will excrete ammonia - additional load on tank.

5) Goldfish sucking up gravel are removing small microscopic food from it.