Thanks again for the follow-up message. During today's water change I noticed that part of the injury (the red and white bubble at the end of the fin) had fallen off and was floating in the water. The fin also looks slightly healthier. I've read stories about how the infection can fall off and the fin can self-heal if the fish doesn't experience further stress and so I'm hoping this might be the case for me. My plan is to do a second course of myzaxin in a week's time and minimise disruption to the tank to keep the environment as stress-free as possible.
I'll look into your suggestions for reducing the nitrates. I switched to silk plants a while ago, because my goldfish ate the live plants and created a terrible mess in the tank (it took ages to get the water clear again!), but nitra-zorb sounds interesting.
Thank you very much for replying. The nitrite and ammonia readings are 0 (brand new test kits ordered the other day). I don't currently have a valid nitrate testing kit, but the readings directly from the tap water have always been on the very high side due to using London tap water (this has never been a problem for the goldfish). I transferred the original filter media to the new tank and so I am confident that the tank has not started a new cycle.
After doing some more research I'm wondering if the disease is Lymphocystis? The symptoms are close to what I can see on my fish (bubbly, boil-like growths). Unfortunately there does not seem to be a cure but can be triggered by stress. I'm wondering if the stress of the tank move caused this?
I moved my two 14 year old goldfish into a new 180 litre aquarium last week, ensuring that the majority of the original water was moved into the new tank. Last weekend I noticed some growths on the front fin of one of the goldfish (see photo). Does anyone know what it is and how to treat it?
The goldfish is not bothered by the growths (it is still eating and swimming normally). The KH and nitrite readings are normal. I have just completed a 5 day course of myzaxin, as suggested by my local aquarium shop, but it has not made a difference.
Re: Alternative to Omega One Sinking large goldfish pellets in UK?
Thank you for your reply. I'm ideally looking for a smaller tub. I can't really justify spending over £30, because I'm unlikely to be able to use all of it before it expires. I generally get through a 226g pot every 4-6 months. The other links unfortunately only list floating pellets, which tend to clog up my filters, or very small sinking pellets.
Alternative to Omega One Sinking large goldfish pellets in UK?
I no longer appear to be able to buy Omega One large sinking goldfish pellets in the UK. Can anyone recommend an alternative or advise on any places that still stock it? All of the other foods I have found are either floating pellets or very small sinking pellets which are too small for my large goldfish.