White bump on Zebra Danio’s head

[siggyllama]

Hi there, new poster here and I could use some diagnosis/treatment advice, in case my other fish are at risk. Any help greatly appreciated.

1~What type of fish is afflicted? In addition, please describe what is wrong with the fish to the best of your ability (i.e. cotton like growth, bloated, etc.).

I added 5 Zebra Danios and a mystery snail to a newly cycled 10gal quarantine tank on Dec. 20 before they’ll get transferred to my main tank. Everything seemed fine up through yesterday, when I did a 33% water change & gravel siphon.

At noon today, I found one of the danios on the filter intake. Fished him out with the net, and saw a white glassy bump on top of his head. (pic attached)

The other four are behaving fine; they have tiny
whitish spots (not raised) on top of their heads, which for all I know is perfectly normal on a zebra danio. (The snail has even been active.)

2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)? Please give exact values

Ammonia: 0
Nitrites: 0
Nitrates: 20
Ph: 7.2
Temp: 68 F

3~ How large is the tank? How long has the tank been set up?

10gal. Cycle established Dec. 19. Zero Ammonia/Nitrites since.

4~What type of filtration are you using? Please give the name and number (i.e. Fluval 304) and amount of gph if known.

HOB Aqueon QuietFlow 10

5~How many fish are in the tank? What kinds of fish are they and what are their current sizes?

Until this casualty: 5 zebra danios (1 inch each), 1 mystery snail (less than 1 inch diameter).


6~When is the last time you did a water change and vacuum the gravel? How often do you do this? How much water do you remove at a time?

I did a 50% w/c on Dec 20 (before the fish went in), a 33% w/c yesterday, vacuuming gravel each time. Tap
water treated with Seachem Prime (same as main tank).

7~How long have you had the fish? If the fish is new, how did you acclimate it/them?

Let bags float in water in water on Dec 20, added 1/2 cup aquarium water every 15 minutes, released from bag after 45 mins.

8~Have you added anything new to the tank--decor, new dechlorinator, new substrate, etc.?

No.

9~What kind of food have you been feeding your fish, have you changed their diet recently?

Aqueon goldfish flakes, Omega One color mini pellets, occasional frozen blood worm.


Thanks for any advice. I have KanaPlex on hand but haven’t added it yet.

 

[Goldfishexxpert]

My goldfish had this before, I just got ick medicine and put him in a sick tank for a week constantly adding that ick medicine and it faded a bit, I’m not too sure what it was but he never lost his appetite nor his energy

 

[siggyllama]

Thanks, that’s encouraging if it ever shows up in the others. Of course, these are in the sick tank; they’ll join a single-fin goldfish in a 40gal tank eventually.

I guess I have three specific questions:

1. Should I treat the surviving danios as a preventative measure?

2. Do I have to start the quarantine period all over again now?

3. Is 4 danios enough for a shoal? My goal is to end up with 10 in the main tank; I was going to add 5 at a time. Can I add these 4 at first, then add 6 in the next step? Or should I bring this batch up to 5 now (especially if I have to restart their quarantine?).