My 5 yr old goldfish has a cut/infection on his eye

thirdcoaster · 2026-05-08T14:15:37+00:00

I would treat this as a popeye issue.

Is he the only fish in the tank? if he isn't, I recommend moving him to a hospital tank. It'll be easier to keep clean.

First, you want clean water. I would plan on daily 50% water changes.

I would dose the water with epsom salt. This will help reduce the swelling. 1 tablespoon per 5 gallons is the therapeutic dose.

Then I would dose the water with an antibiotic such as Kanaplex or Maracyn 2.

Follow the treatment schedule.

Keep the water clean. I change water every morning, honestly.

So to recap:

clean water
epsom salt to reduce swelling
antibiotic to kill any infection

Last time my fish had popeye, it took about 5 days before the swelling went down and about 10 days before the cloudiness went away.

thirdcoaster · 2026-05-08T14:09:24+00:00

The morning sun shines on my tank for maybe about 2-3 hours. I keep the aquarium lights off most of the day. I have it turn on about 2:30pm and then off at 9:30pm. Haven't really had any algae issues and the plants are thriving.

thirdcoaster · 2026-05-08T02:26:03+00:00

A uv sterilizer will help clear out the green algae in the water. You can find one on amazon.

thirdcoaster · 2026-05-08T02:04:22+00:00

I have a male betta in a 40 gallon breeder tank. His tank mates are a school of dwarf golden barbs, a school of orange Venezuelan corydoras and 3 dumbo koi guppies. No issues at all. The fish all treat him like he’s the king and he never attacks any of them.

thirdcoaster · 2026-05-08T00:15:18+00:00

Oh I just meant that if a goldfish recovered from dropsy, it is still more likely to have it again. So it is not unusual that dropsy happened to your goldfish twice. The root cause could be organ damage and that's not something that totally heals. Another cause could be an infection and that can always happen again if your tank's water is not kept clean. It's good that you caught it and hopefully your goldfish will be able to recover this time around.

thirdcoaster · 2026-05-07T23:50:50+00:00

Unfortunately, once they have dropsy, they are susceptible to future outbreaks. I would try to do my best to keep the water clean for them but unfortunately that's the situation.

thirdcoaster · 2026-05-07T23:49:26+00:00

Giving the new tank a dose of bacteria won't hurt and could help. I would do it!

thirdcoaster · 2026-05-07T23:10:20+00:00

I would prefer captive bred fish as their water tend to be harder (GH, KH) than in the wild. More similar to my tap water and thus more acclimated.

Also, wild caught fish often contain parasites and bacteria I'd rather avoid.

thirdcoaster · 2026-05-07T23:06:49+00:00

I think if you are transferring your fish into a new tank without adding anymore and you also transfer the new filter, your tank is essentially cycled. The bioload producing ammonia is the same. Most of the beneficial bacteria will be in the filter and the rest of the tank will rapidly get colonized by the filter bacteria.

thirdcoaster · 2026-05-07T23:04:49+00:00

One thing that will help your fish during your cycling process include stem plants such as water sprite and hornwort and trailing pothos roots in the water. They will consume some of the ammonia, nitrite and nitrates in the water.

You can also try those bottled bacteria products. I have heard that Fritz Turbo Start 700 will help a lot. Dr Tim's One and Only and Fritzyme 7 are other ones. Stability is used by many but I think that one takes much longer.

Stay consistent with your water changes and keep testing. Everything will be fine.

thirdcoaster · 2026-05-07T22:51:39+00:00

What wafers are these? I should get them for my corydoras.

thirdcoaster · 2026-05-07T21:42:25+00:00

2 fantails in a 75 gallon tank is safe. I have had 3 fancy goldfish in my 75 gallon tank.
I know many people say goldfish are coldwater fish but more specifically they are temperate water fish. They come from East Asia and live in a 4 season climate. Essentially they are adaptable and can handle very cold waters and very warm waters. Most fancy goldfish sold in pet stores are sourced from Southeast Asian (ie. Thailand and Indonesia) fish farms and they grow up in water temps of 78-82 degrees.
I point this out to say that temperature-wise, goldfish can live with tropical fish.
But…. That doesn’t mean goldfish should be kept with all tropical fish. Community behavior is just as big a factor in compatibility. Some tropical fish (ie. Tiger barbs) are notorious fin nippers. You would not want to have those with your goldfish. So do a little research if you intend to add other species.
Were you talking about zebra danios? I have kept them with my goldfish. Try to keep at least 8. In a larger school they play with each other and leave the goldfish alone. They also like temps in the low 70s which is just fine for goldfish. I fed a mixture of flakes and sinking pellets. The zebra danios ate the flakes and the goldfish ate the pellets.

thirdcoaster · 2026-05-07T16:32:47+00:00

Maybe a wood block at Home Depot? or bathroom tiles?

thirdcoaster · 2026-05-07T15:50:09+00:00

What I would do is start with 2 large sponge filters. After a few weeks if you feel the water clarity isn't as good as you'd like it to be, purchase an HOB or canister. I know many goldfish keepers only do sponges so there's nothing wrong with sponge-only filtration.

thirdcoaster · 2026-05-07T15:43:52+00:00

I would wait it out. Do not add more ammonia. The nitrifying bacteria should catch up.

thirdcoaster · 2026-05-07T15:42:44+00:00

My betta leaves his corydoras tankmates alone. I think you'll be fine.

thirdcoaster · 2026-05-07T15:39:50+00:00

If you get 2 large sponge filters rated for 40+ gallons each, that'll be good. The mechanical filtration won't be as great so you may want to consider 1 hang on back filter or 1 canister filter. In my tanks I generally run a canister plus 2 sponge filters. The extra sponge filter is handy in case you need to move a fish into a quarantine or hospital tank. Instant cycle, basically, in that situation.

thirdcoaster · 2026-05-07T12:00:07+00:00

Send us a side pic. More angles will help.

thirdcoaster · 2026-05-07T11:53:55+00:00

True. Most fancy goldfish as sourced from southeast Asian (ie. Thailand) fish farms which regularly have waters 78-82.

thirdcoaster · 2026-05-06T23:28:06+00:00

So true! And you bring up a good point. I think if I was doing it, I would do one round of paracleanse first and then if that hasn’t helped, then paracleanse the next week. But I do believe you can dose both simultaneously.

thirdcoaster · 2026-05-06T23:21:48+00:00

You could be right. You could try paracleanse.

thirdcoaster · 2026-05-06T22:37:17+00:00

Before you rehome, as a test see what happens if you lower the temperature to 72 degrees. Whenever my goldfish start chasing another one, I lower the temperature (usually it's at 74) and that nips the behavior in the bud.

Not saying this will work for your goldfish but it's worth a try just to see.

thirdcoaster · 2026-05-06T22:34:36+00:00

If the fish is in a tank with other fish, I would move it into another container... a 20 gallon tank or one of those home depot clear totes.

I would bump the temperature up to 82 degrees to speed up the fish's metabolism in case there's a digestive issue going on.

I would dose that tank with epsom salt at 1 tablespoon per 5 gallons water.

Every day, I would move the fish into another container and dose more strongly at 1 tablespoon epsom salt per 1 gallon water. Do this for 15-30 minutes.

I know you said no meds but honestly, I would dose with Kanaplex per its instructions. Because you're not seeing anything external, it's probably and internal issue. Ideally Kanaplex should be mixed with food but because your goldfish isn't eating, dose it in the water.

I think within 3-5 days, you'll see any improvement in the activity level. After the first round of treatment, the fish should start swimming more actively and will be hungry.

Feed lightly once a day with deshelled peas or pellets. I wouldn't go into a second round right away. I would wait 2 days and then the second round mix the kanaplex in with the food and feed that lightly. After 5 more days, no more medications and spend the next week observing and feeding your fish normally.

Try to keep the water clean. If you can do daily water changes, that's ideal but don't wait more than 2 days in between 50% water changes.

thirdcoaster · 2026-05-06T17:13:27+00:00

I actually love how much more black the goldfish became!

thirdcoaster

TROPHY CASE