Platy with Whitish Spot on Chin

Tank size: 10 gallons
pH: don’t know
ammonia: 0 ppm
nitrite: 0 ppm
nitrate: <5 ppm
kH: don’t know
gH: don’t know
tank temp: 75 F

Fish Symptoms (include full description including lesion, color, location, fish behavior):

Ok here’s the story folks. I’ve been planning to add another platy to my tank, went out and got it today. I don’t have a hospital/quarantine tank (I know...bad...parents won’t let me but I honestly would smuggle a 2.5 g in at least if I thought I could get away with it).

So I acclimated the fish and put him in my tank, and later I was watching him and saw a...spot...a teeny tiny spot, almost too small to tell but it’s definitely there, on his chin (not his mouth). Whitish. I noticed it because it protrudes ever-so-slightly.

I then went online to try to figure out what it was, freaked out and scooped him back out of the tank (where he was finally beginning to relax) and put him in a plastic critter keeper because I’m paranoid he’ll infect my other fish.

He has no other white spots. No fin clamping. He is obviously pretty traumatized by the whole deal and is currently trying to hide in some frogbit I put in with him, but he was swimming around fine in the tank. Overall, he actually looks healthy. The white spot wasn’t visible in the store (or on any other fish in the tank), or I wouldn’t have bought him.

Volume and Frequency of water changes: 50%, last one was 3 weeks ago (I do 1 part tap water 2 parts RO because my tap has super high nitrate)

Chemical Additives or Media in your tank: Seachem Prime with each WC

Tank inhabitants: 3 platies, pest snails

Recent additions to your tank (living or decoration): the sick (?) platy

Exposure to chemicals: none I’m aware of

Digital photo (include if possible):

Ok he looks like death in these pics, but he’s not. Those other white flecks are dust on the outside of the tank. This was immediately after I’d put him in the plastic tank and he was a bit freaked. He’s swimming around in there calmly now:

What should I do? I know he can’t stay in there long, and my other fish were already exposed for a few hours to whatever he’s got. Should I just put him back in and treat the whole tank? How do you even treat this? It looks small and harmless right now but I really don’t want it to get worse, and I really really don’t want to lose any fish...

Edit: I begged and pleaded and convinced my parents to let me get a 2.5 gallon quarantine tank (after my other fish have already been exposed, of course...). Setting that up now.

It's not a disease as such and most likely just a bump or graze that has excess mucous to help protect it. I would put the fish back in the main tank and monitor it.

I would do a 75% water change and gravel clean the substrate each day for a week, and then do it every week after that. Doing a water change once every 3 weeks is not good for the fish. Try to do it every week.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

If the filter has been running for more than 2 months, clean it if it hasn't been done in the last 2 weeks. Wash filter materials in a bucket of tank water.

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You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

Colin_T said:

It's not a disease as such and most likely just a bump or graze that has excess mucous to help protect it. I would put the fish back in the main tank and monitor it.

I would do a 75% water change and gravel clean the substrate each day for a week, and then do it every week after that. Doing a water change once every 3 weeks is not good for the fish. Try to do it every week.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

If the filter has been running for more than 2 months, clean it if it hasn't been done in the last 2 weeks. Wash filter materials in a bucket of tank water.

--------------------------
You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

Click to expand...

Oh, that’s a relief to hear! I’m glad it’s not something contagious!

Okay, daily 75% wcs for a week. (I do normally do weekly changes, I promise—nursing school has been kicking my butt this month.) Is there a reason why water changes still need to be done if ammonia and nitrite are 0 and nitrate is close to 0? (I’m not trying to argue, just curious—I’m still fairly new to the hobby.)

Do I add salt in again with all the water changes, to keep it at the same level? I do only have platies in that tank, so I can do the higher dose if need be. I was hoping to add cherry shrimp to that tank in a couple months. Could any lingering salt affect them?

Big daily (or every second day) water changes dilute nutrients and disease organisms in the water, and this helps fish heal faster.

If you are adding salt, then you need to add it to the new water each time you do a water change so the salt level remains constant for a couple of weeks. Then you can stop adding salt and do water changes to dilute it out. After 5 or 6 big water changes there won't be much (if any) salt left.

Colin_T said:

Big daily (or every second day) water changes dilute nutrients and disease organisms in the water, and this helps fish heal faster.

If you are adding salt, then you need to add it to the new water each time you do a water change so the salt level remains constant for a couple of weeks. Then you can stop adding salt and do water changes to dilute it out. After 5 or 6 big water changes there won't be much (if any) salt left.

Click to expand...

Ah, that makes sense! Thank you!

The whitish dot is bigger today. Probably about a millimeter out from his face (I can’t get a good picture; he’s been lurking in the back). It looks less rounded too. It’s making me a bit nervous. Honestly, I’m starting to wonder if I should just take him back to the store. I don’t want to but I’m nervous about my other two fish getting infected if it is something contagious.

You can contact the shop and ask them if they will swap it.

If you have salt in the water it should help reduce the number of disease organisms in the water.

Colin_T said:

You can contact the shop and ask them if they will swap it.

If you have salt in the water it should help reduce the number of disease organisms in the water.

Click to expand...

Yeah, I ended up returning the fish and continuing with the rest of your advice. It probably would’ve been fine, I just didn’t feel able to nurse a wounded/sick fish at the moment.