Fancy goldfish question!

[irunwithgoldfish.]

So, I set up a new 10 gallon tank and had it running almost 2 months ago, in the hopes of getting 2 feeder goldfish. I have 2 filters running (both for a 15 gal. tank), a double air pump with an airstone strip, and a heater that stays on 70.
A week ago, I went to Petco to get the fish, but instead ended up adopting 2 fancies, a fantail & oranda. They were both in terrible condition, including split fins, fin rot, black spots etc. I didn't have the heart to leave them there. After treating them with Melafix and partial water changes everyday, both of their fins are almost perfectly healed and are much more active.
Now for my question, my fantail had a black spot about a centimeter long on the base of his dorsal fin that I noticed before I got him, I assumed it was just a marking, but today the spot has moved to the tip of his fin and appears to be going away. I don't know if this is normal, these are my first ever fish and I've read of ammonia burns on the tips of fins, I just want to know if this isn't something I should be worrying about. Any tips would be awesome. please & thank you.
oh, and I plan on getting them a 30 gal. very soon. :3

 

[Mumma.of.two]

So, I set up a new 10 gallon tank and had it running almost 2 months ago, in the hopes of getting 2 feeder goldfish. I have 2 filters running (both for a 15 gal. tank), a double air pump with an airstone strip, and a heater that stays on 70.
A week ago, I went to Petco to get the fish, but instead ended up adopting 2 fancies, a fantail & oranda. They were both in terrible condition, including split fins, fin rot, black spots etc. I didn't have the heart to leave them there. After treating them with Melafix and partial water changes everyday, both of their fins are almost perfectly healed and are much more active.
Now for my question, my fantail had a black spot about a centimeter long on the base of his dorsal fin that I noticed before I got him, I assumed it was just a marking, but today the spot has moved to the tip of his fin and appears to be going away. I don't know if this is normal, these are my first ever fish and I've read of ammonia burns on the tips of fins, I just want to know if this isn't something I should be worrying about. Any tips would be awesome. please & thank you.
oh, and I plan on getting them a 30 gal. very soon. :3

Hi!
Do you have a test kit? It does sound like ammonia burns. That's great your getting an upgrade. The sooner the better IMO. Do your know about the nitrogen cycle? How did you cycle your tank?
http://www.aquariumadvice.com/artic...-to-Starting-a-Freshwater-Aquarium/Page1.html

 

[irunwithgoldfish.]

Hi!
Do you have a test kit? It does sound like ammonia burns. That's great your getting an upgrade. The sooner the better IMO. Do your know about the nitrogen cycle? How did you cycle your tank?
Guide to Starting a Freshwater Aquarium

I'm getting a test kit this weekend & yes, I know about the bacteria, nitrates, nitrites, etc. I wasn't really sure how to cycle it, so I just let the tank run for a few weeks, dropping in a pinch of sinking food pellets every few days.

 

[irunwithgoldfish.]

the day I got them,they would never leave eachother.

 

[irunwithgoldfish.]

This is them today, in much better shape.

 

[Mumma.of.two]

I'm glad they are doing much better. I'd advise daily water changes until you can get your test kit. That way you don't have to worry if there are toxins in the water or not.