You said you have artificial plants in your tank...so it is ok to take them out, clean them (not with soap, just with your fingers, under the tap) and put them back in just so you can make sure you won't have any problems.

As I said I can only give you advice from what I have seen with my own eyes...most of the eggs that seemed clear but had a white spot inside them, in the beginning, actually ended up being unfertile eggs...but if you have that anti fungal med the fact that some eggs are unfertile shouldn't be a problem, because they won't get fungus that can be transmitted to the fertile eggs...I will post a picture I found on the web showing the unfertile eggs with fungus:

image

I hope this helps on establishing the eggs status!

I am sorry I didn't realize what itsy did: you didn't quarantine the new fish? As she said this is very dangerous for the fish you have at home..a lot of fish that I had over the years died because of my lack of knowledge and experience...and usually after introducing new fish or plants without quarantine! I now have some snails that are waiting for homes in my tanks, but I'm keeping them in a QT although a friend that has healthy fish gave them to me!

I also don't think that keeping 6 goldies in a 190 liter (50 gallon) tank is very well...at that capacity you should have 4 or at the most 5 goldies if they are smaller...I will have to quote others on this forum: "goldfish should have 10 gals each at the very minimum - 15 would be better; they are very big waste producers and can foul a tank in no time."