Fuzzy white growth developed AFTER using Melafix for fin rot?

Hey all! I have a ten gallon tank (cycled, filtered, and heated) with a blue dwarf gourami and a golden mystery snail. We'd had a pest snail infestation that got out of control so I moved the fish and "friendly" snail and cleaned the whole tank out top to bottom (kept about 50% of the original water and replaced the other 50%) last Tuesday. On Thursday morning (7/16) I noticed that there was some darkening/damage on the gourami's top fin. I assumed that he had either hurt himself on some new decor or it could be fin rot due to the stress of the move, and began dosing the tank with melafix and monitoring the water quality (which has been fine--the nitrate was initially a bit high, but it's gone down). While the dark spots haven't really gone away, he's returned to a more active demeanor so I haven't been too worried and have continued giving the recommended 5ml dose of Melafix daily. This morning (7/20) when I took a look at him, he has developed a fuzzy white growth on that dark spot on his top fin! I thought that fungal issues were something that Melafix was supposed to treat and prevent, so I'm alarmed that it's happened while I've actively been dosing the tank. I just wanted to know if anyone has had any experiences with this or any suggestions with how to proceed--if I just keep giving it to him, should the growth go away? Is there anything else I should be doing to try and help him out?

 

Hey all! I have a ten gallon tank (cycled, filtered, and heated) with a blue dwarf gourami and a golden mystery snail. We'd had a pest snail infestation that got out of control so I moved the fish and "friendly" snail and cleaned the whole tank out top to bottom (kept about 50% of the original water and replaced the other 50%) last Tuesday. On Thursday morning (7/16) I noticed that there was some darkening/damage on the gourami's top fin. I assumed that he had either hurt himself on some new decor or it could be fin rot due to the stress of the move, and began dosing the tank with melafix and monitoring the water quality (which has been fine--the nitrate was initially a bit high, but it's gone down). While the dark spots haven't really gone away, he's returned to a more active demeanor so I haven't been too worried and have continued giving the recommended 5ml dose of Melafix daily. This morning (7/20) when I took a look at him, he has developed a fuzzy white growth on that dark spot on his top fin! I thought that fungal issues were something that Melafix was supposed to treat and prevent, so I'm alarmed that it's happened while I've actively been dosing the tank. I just wanted to know if anyone has had any experiences with this or any suggestions with how to proceed--if I just keep giving it to him, should the growth go away? Is there anything else I should be doing to try and help him out?

Can you show an image? It would be very useful. Also please fill out the emergency fish forum.

Fish Emergency Template | 376562 | Freshwater Fish Disease and Fish Health

 

Sure thing! Images attached. Sorry they aren't great-- he moves very quickly and my phone is very slow. I just did a water reading and found the ammonia was much higher than it's been (1.0), so I suspect that may be part of it, but still feel uneasy that it would happen while also medicating him. I just did a 25% water change and will watch for changes over the day.

Sorry--I didn't realize there was a form! I've filled it out below.

Tank

What is the water volume of the tank? 10 gal
How long has the tank been running? 1 month / 5 days since reset
Does it have a filter? Yes
Does it have a heater? Yes
What is the water temperature? 85 F
What is the entire stocking of this tank? (Please list all fish and inverts.) 1 Dwarf Gourami and 1 Golden Mystery Snail, both introduced at the same time.

Maintenance
How often do you change the water? Weekly, but I've been doing a 10% daily change since cleaning the tank.
How much of the water do you change? Typically 10-25%
What do you use to treat your water? Tap water conditioner and quick start
Do you vacuum the substrate or just the water? Mostly water. I do as much of the substrate as I can but I know it's not getting everything.

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? Previously test strips, currently API freshwater master test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.

As of today (I know the ammonia is a problem--doing changes to fix it)
Ammonia: 1.0
Nitrite: 0
Nitrate: 0
pH: ~7.0

Feeding
How often do you feed your fish? Twice/day (and one algae pellet per day for snail)
How much do you feed your fish? Very small pinch
What brand of food do you feed your fish? Aqueon tropical flakes
Do you feed frozen or freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? 1 month
How long ago did you first notice these symptoms? Fin damage began 4 days ago, white growth began today
In a few words, can you explain the symptoms? What looks like fin rot beginning after a large tank change (maintaining 50% water) I've been treating it with Melafix but today (after 4 days of treatment), it seems to be getting worse, with a fuzzy white growth.
Have you started any treatment for the illness? 4 days of Melafix. 5ml in morning and 1/2 ml in the evening after water changes.
Was your fish physically ill or injured upon purchase? No.
How has its behavior and appearance changed, if at all? He had been hiding and breathing a little hard on the first day, but has since returned to normal behavior.

 

Seems like a fungal infection but could be bacterial, try a fungal med/antibiotics instead of melafix as melafix is basically just some ‘soothing tea tree oil’ and doesn’t contain any actual medicine.. I’m not really sure what specific meds are good for this type of thing so hopefully someone else can answer for me! I hope your gourami gets better soon

also the difficult breathing could be due to the melafix as less oxygen is diffused into the water and I think it also creates a layer over the water’s surface

 

Unfortunately Melafix was scientifically studied and found to have no medicinal benefits whatsoever for fish. Mars, who owns API, actually helped fund the study, perhaps expecting a different outcome. They did find it smells nice and is perfectly safe for goldfish however.

https://www.researchgate.net/publication/275258014_Laboratory_evaluation_of_safety_and_efficacy_for_MELAFIXR_melaleuca_cajuputi_extract