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Melafix kills pencil fish

AlecF

Member
Joined
15 Sep 2021
Messages
568
Location
Edinburgh
I just lost 3 pencil fish to melafix, being unaware of the reports of issues. The rest are gasping and losing colour. API deny there is an issue, but my fish were healthy and died within 30 minutes. They are irresponsible and should be ashamed. Share the information. As melafix is basically tea tree oil I need advice how to remove it – I have done a 90% water change, but the oil is mostly on the surface. Should I skim off? Will any tank additive help? I hope the rest of my fish survive. I don't know if their gills will be permanently damaged.
 
Hi
You could try kitchen towels to remove the oil on the surface..... and charcoal in the filter!
Add extra aeration on the surface or with a air stone/air-pump.
 
Thanks. I have a lot of filtration disturbing the surface – an Eheim and a Fluvial 107 with spray bar. I just recently started a new QT tank but added ammonia, so it isn't ready yet, sadly. I do have one other tank, a small 25 litre nano, with least killifish, fry, shrimp, and shrimplets – I suspect the M pencils would cause havoc in there as they are feisty. It's a tough choice. I lost another fish, so that's at least 4 gone. I will try paper towels, but I think perhaps taking water from the surface with a small jug may work just as well. One fish is looking poorly and the other 3 seem not as bad. We'll see who is left alive in the morning.
 
Hi all,
I just lost 3 pencil fish to melafix, being unaware of the reports of issues. The rest are gasping and losing colour. API deny there is an issue, but my fish were healthy and died within 30 minutes.
Sorry for your loss, that definitely sounds like an oxygen issue. If the fish have been exposed to high ammonia (NH3) or chlorine (Cl2) levels in the recent past (during transport?) they may have had gill damage, reducing their ability to absorb oxygen.
I will try paper towels, but I think perhaps taking water from the surface with a small jug may work just as well.
That would be what I'd do, both paper towels and a jug.
I just recently started a new QT tank but added ammonia, so it isn't ready yet, sadly.
Not very useful for you at the moment, but I don't have a specific quarantine tank, I just have a <"spare planted tank">. It is same as all the other tanks, but without <"any permanent inhabitants">. It is usually my <"Jenga"> and spare sponge tank and it has a filter, <"tank janitors"> etc.

A lot of people think that a filter/tank kept like <"won't be "cycled">, because it hasn't had an ammonia source, but this just isn't true. A grown in planted tank will have plenty of biofiltration capacity.

cheers Darrel
 
Thanks. From all reports it is an issue with tea tree oil affecting their breathing, ie the way this species breathes. So yes, they died of lack of breath. They weren't newly arrived; I'd had them between 1-2 months – they were super healthy and rather too feisty. The effect of the oil wears off after 24 hours, so half lived and half died. I am setting up a spare tank, with plants, which has almost cycled, but sadly it wasn't ready when the melafix disaster occurred. The main thing is to warn people about malefic and pencil fish, also, I believe, gourami. My impression was that whatever method you used wouldn't be rapid enough, the only thing that could save them was immediate removal.
 
Hi all,
, also, I believe, gourami.
Gourami (and other Anabantoid fish) have a labyrinth organ that allows them to take atmospheric oxygen from the water surface, and that maybe where the issue is. I definitely wouldn't use Melafix etc with Betta spp.

I'm not sure with the Pencil fish (Lebiasinidae), they are close to Tetras and just have standard gills. They live near the water surface, so they may not have as much gill volume as fish that live nearer the bottom in still water, where there are lower rates of gas exchange. It might be that some of the problems people have with just keeping Pencil and Hatchet fish alive are oxygen related, as they both do well in planted tanks, where oxygen levels are likely to be higher.

Fish that are particularly at <"risk from hypoxia"> are fish from <"cool, clean, rapidly flowing water">, because they never experience low oxygen levels.

cheers Darrel
 
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Yes, when you see it happen the issue is as clear as day, or death. The other fish were fine, but the pencils were gasping, swimming upside down, then half of them dead. No issue with corys (despite their method of breathing), peacock goby or amano. The problem is how to get API to issue a warning, as they should do. I've written them and am awaiting a reply. In retrospect I should have just fished them out into a bucket of water with a heater and some 'safe'. Even then I would have lost some as the effect was so rapid. It's one of these cases where it would be good if we accepted the issue as a fact and make it well known.
 
Keep doing water changes, large ones.

Yes, Melafix and Bettafix are only oils and they yea, they kill fish. Will never change my opinion, I heard a lot of horror stories about those two "meds".
 
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