Feeding enough, and injuries

Question
QUESTION: I'm a bit of an amateur, so I hope these are easy ones:
1) I have one small koi, one unknown type of goldfish (pearlescent white, with one crimson spot on his head like a redcap oranda, but with the normal goldfish physique) and one shubunkin, and they seem to be always pushing around the tank gravel, searching for food. I'm concerned about whether or not this is normal, or if I am not feeding them enough. They fight a bit over food as well -- particularly the larger shubunkin. Nothing harmful, just a bit of pushing the others around.
2) The unknown goldfish seems to have injuries on both sides of his body. Is there anything I can do to help it heal?
Thanks.

ANSWER: I first want to apologize for the delayed response. I have been having computer issues. Anyway, it sounds as if you are doing well with feeding your fish. The majority of people feed their fish way to much, which leads to problems. It is great that your fish are active and are aggressive feeders. This behavior shows that they are in great health. Nothing to worry about. IF you have the portion sizes down, which is sounds like you do, then I personally wouldn't recommend yo feeding the fish more than 2 times a day, portions considered. I believe you are doing fine. If you ever have any questions in the future, feel free to contact me. Good luck

---------- FOLLOW-UP ----------

QUESTION: Sorry for another amateurish question, but I'm having a serious problem with
one of my fish. Or, well... one of the fish NOW. I bought a few additional fish
for my tank, three small feeder goldfish and two 1-inch shubunkin. I bought
an automatic feeder (and tested it beforehand) and returned from
Thanksgiving travels to find one of the small fish dead. Every day after that
for 5 days one fish died. I tried everything within my means... water changes,
tank cleanings. Their bodies showed no signs of stress or injury, so I was
perplexed. None have died for about a week now, to my relief. I totally
cleaned the cage, filter, filter insert, cleaned the gravel, everything. (I simply
rinsed the gravel though, to save some bacteria, which I've heard is needed).  
Everything is good now, save for one fish, who is in very bad condition. It's a
Sarasa Comet, and it hasn't been eating for the past two or three days.
Anything it gets into its mouth, it spits back out. Its scales have always been
odd -- I think it sustained injuries when I first set up my tank, but I can see
them starting to heal -- but I've noticed in the past few days its tail is in a
really bad state. It has many white-lined tears in its tail and fins. Otherwise,
its behavior is sluggish and it lurks at the surface of the water, gasping for
air. I feel horrible because I'm a college student, I don't have the means to set
up a quarantine tank. The weirdest thing is that whatever is affecting the
Sarasa Comet isn't spreading to the 3 other fish in the tank. I've been
researching fish diseases, but I can't pinpoint a single one. (It is also
experiencing long, pale feces, as I noted in one disease symptom). Any help
would be appreciated. He's my favorite fish, and I don't want it to die.

Answer
Well, without hesitation, i am willing to bet that you have an unsafe ammonia, and nitrite spike in your aquarium water. This will definitely kill off all of your fish without and signs of sickness. I would urge you to test the water quality before doing anything further. If the environment the fish are living in is unhealthy, they are most certain more prone to illnesses. The signs on your fish's tail and sluggish movement indicate that it may be suffering fin and tail rot. I would recommend you administer Maracyn as described on the package. Also, I would recommend you use an additional medicine which is also from Mardel brand called, Maroxy. This is a broad spectrum antibiotic. You just have to be the judge of whether treating an illness is more suitable than purchasing a new fish.