Visible veins in fins of fantail goldfish

Question
Hi Stephanie
I have had a 5 gallon hexagonal tank with built in filter and light for around 3 months now. We started with one fantail - phunkee, left him for about 2 weeks then added a pearlscale-Joe and a wakin - Bob(I think it is a wakin - it looks like it anyway from website photos). Within a couple of hours 'someone' had attacked the pearlscale and eaten his eye. This resulted in a second new tank but ultimately 'One Eyed Joe' passed on. I don't think he ever really recovered from the attack.

Anyway we then bought another fantail - Freda, and put it in the tank with Bob and Phunkee at which point Bob went crazy and started to torment the other 2 relentlessly. I tried seperating them and putting them back together but it didn't stop. The other tank is being used as a tropical now (with heater etc and 5 happy tetra's) so ultimately Bob went back to the fish shop and they replaced him with another fantail - Nelson. (again 3 in the tank - I hope this is clear!)

Freda suddenly developed some spots on her skin which I noticed early in the morning, but I was away for the next 2 days and when i returned it looked like she had quite serious fin rot. Could this be caused by Bob bullying? The water quality seemed fine. I also noticed that both Phunkee and Nelson had visible red veins in their fins. I bought the finrot medication but it was too late for Freda.

They told me in the shop to take the filter out of the water whilst I am medicating, so it has been 4 days now. Phunkee and Nelson are looking a bit happier but not perfect although they are both eating and seem to be lively. My questions are:
Do you know what is causing their veins to show - is this normal or serious? I have tested the water and all is fine.

Also do I have to leave the tank for 7 days with the finrot medication in as the other 2 don't seem to be suffering from finrot, and without the filter the tank is looking a little dirty. I have left the filter running just taken the carbon filter, sponge and balls out.
I realise this is very long and I hope it is clear but if you could advise I would be very grateful.  

Answer
Hello,

I personally have never had any experience with 'veins' in fins, but here are a couple things that might help:

There are three catergories a fish disease can fall under; parasites, bacterial or fungal. Funguses will appear as white- whether white tufts or a white foggy eye. Parasites will most likely be speckles or dots, because they are actually little insect like beings. Bacteria cover everyting in between. Since the veins aren't white, they can't be fungal. They obvioulsy aren't bugs so can't be parasitical. We must then assume it is a bacterial based disease and you should treat it likewise. I recommend Melafix, which is an all around antibacterial that is very natural.

I'd recommend stopping the finrot medication while you are using an antibacterial, but I suggest you put at least part of your filter back together. If your fish aren't in immediate danger, put the whole thing back but if you really want the medicine to work fast and to its fullest potential, just put everything back in your filter except the carbon/zeolite. Those are what would filter out the medications. At the very least you should have the sponge still in your filter.

I hope this helps a little and that you can successfully diagnose the problem before another fatality. Best of luck.

From Stephanie