Hello everyone
I want to buy 2 fantail for my new cycled 125l fish tank, the problem is, at least 2 of them in the aquarium display of the lfs have some kind of diseases: one has a white patch over the head (fungus?)and the other one has a black patch on its mouth (ammonia burn?).
If you confirm my suspisions ,could you please advice on the correct way to deal with those problems ? I suppose they could have ick and other unseen nasties like internal parasites.

I only have aquarium salt, flagyl 250mg(metronidazole) and methylene blue , the praziquatel is not available where i live . I have never used them because this my first fish tank.
Thank you in advance

Ps : the fish tank has an over head filter that holds a lot of ceramic rings cycled more than 1.5 month filter floss , jebo 375 water pump and a bubbler, medium size gravel ( aprox 3 cm depth)

I'm not entirely sure from your post whether (i) you want to buy the fish but haven't yet because you're wondering how you might treat them if you do or (ii) you have already bought them.

Whichever is the case, the number of fish you have in that 125 litre tank is far too many - and the fish are never going to be healthy. Water quality needs to be consistently and permanently as follows: ammonia and nitrite at 0 ppm; and nitrates less than 20 ppm (or no more than 20 ppm above tap water nitrate levels). You'll need to have a liquid test kit to measure this daily, and do whatever number and quantity of water changes are required per week to ensure that water quality does not creep up at all above those levels. That is the only correct way to address these problems and prevent the other fish from falling ill too.

As soon as you can, please buy a much bigger tank for them - or several tanks with a few of the fish in each. Move the mature filter media from the cycling process to the new tank or split it between the filters of the new tanks.
https://www.fishkeeping.co.uk/modules/ ... esheet.php?caresheetID=83 gives details of the size of tank required for 1 fantail fish, and further details are at https://www.fishkeeping.co.uk/articles ... -size-life-expectancy.htm and https://injaf.org/the-think-tank/how-t ... nditions-can-affect-fish/

Hope this is helpful.

Thanks for your fast response.

My aquarium was fishless cycled one month and half , right now it's empty and i am think about buying from the local fish store one comet or 2 fantails .

I finally decided to get 2 fantails so i contacted the local fish store and they sent me some pics of the available fantails.

As you can see ,they have an overcrowded tank and some of the goldfish have black patchs on their mouth and one of them have the whote patch on the head ( fungus or columnaris ).

Fantails are extremely difficult to find where i live as the demand for them is very high, so i am thinking of buying 2 fantails that does not have any visible disease from that overcrowded tank and treat them in a quarantine tank (uncycled and think of daily water change with dechlorinated water) with the 3 things i mentioned earlier .

That's why i appreciate a course of action to treat the future 2 fantails with epsom salt / metronidazole/ methylene blue to avoid transfering nasties to my 125l cycled tank ,i am aware that i also need a dewormer like praziquantel but the only anti-helminth available is fenbendazole(panacure 2.5%).

I hope you understand my situation.

My sister had a comet goldfish in a 125l tank and lived happily for more than 10 years but did not reach a huge size , Maybe he was stunted. That is the main reason i am trying to get 2 fantails instead of a comet or common goldfish.

Aaah right, now I understand. Thanks for the clarification.

That's a relief to know that the tank is empty and that these are the fish in the pet shop. This should make the situation much easier to deal with.

It is very possible that, once the fish are in your tank (rather than the overcrowded tank of the pet shop), with ammonia and nitrite at 0, and nitrates at <20, the problem resolves itself. However, eSHa 2000 plus some aquarium salt is likely the best option to treat the 2 fantails, rather than the other products you have.

If your newly-cycled tank is empty, then you could just treat the two unhealthy fish in there, rather than setting up a separate quarantine tank. A quarantine tank would only be needed if you were needing to take one of the two fish out of the tank for treatment.

Fantails are indeed the better option for the very reason you state.

Hope that helps.

Indeed, but the esha2000 is not available, could you recommend similar product from sera or jbl?

There is an ornamental fish market in casablanca-Morocco-with a lot of species but i am sure that they don't treat the fish with meds. All the imports are from wholesalers from asia = parasitic infestation is 100% so quarantine is a must but the downside is that only some products from sera (mostly) and jbl are available.

Just a note, but a 125 litre tank is too small for goldfish....minimum is 180L for fancies, bigger for single tails.

I have a brand new 75 gallon fish tank but this one will be used for a dutch style in the near future , right now loaded with 8kg ceramic rings and filter floss , still empty with no water .

The cycled tank contains 125l as i measured the exact amount of water via 5l mineral water bottles and i suppose one fantail could fit there but again the poor thing needs a companion so i thought maybe another fantail could fit there. I will put a pothos plant and some water lettuce to help with nitrate elimination .

Do you still think 2 goldfish in 125l is not possible?

From Sera:
https://www.sera.de/en/product/freshwater-aquarium/sera-omnipur-s/ looks a good, broad-range treatment which might cover all you describe externally at least ie bacterial infections and fungus and some external parasites.
There are individual products for bacterial infections, fungus and various types of internal and external parasites - see https://www.sera.de/en/freshwater-aqua ... aquariums/treat-diseases/ - but I think best to use the Omnipur for now.

From JBL:
https://www.jbl.de/en/products/detail/ ... ranol-plus-250?country=gb for internal and external bacterial infections seems the best but doesn't cover fungus or parasites.

Thanks fcmf

I will look for those products and report back