Help identifying a white spot please - platy

Hello

It is my first time posting and I am wondering if someone can help us please?

One of my daughters platys has a spot on it's tail. It's a dull white colour and doesn't seem to be the same as pictures I've seen of white spot. It seems to be on one side of her tail, it either it slightly raised or clearer to see on that side - it's hard to tell.
It has been there for a few weeks and hasn't appeared to spread. Otherwise she seems normal.
She is pregnant, and last had fry 3 and half weeks ago.

We thought the spot was a bit of dirt/poo after we cleaned the tank and kicked up mess from under the gravel. I expected it to come off on it's own. I haven't been able to get near to the fish to try to gently wipe it off.

Hopefully I've attached some pictures. I'm sorry they're not very clear.

Thank you

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24L tank with filter
25 degrees C
4 adult platies (3 female 1 male)
8 platy fry in a hatchery
Fed fish flakes and sometimes peas
Tetra Ammonia and Tetra 6 in one test strips show tank is ok apart from KH which is high (but not very high or very very high).

Should I start treating the whole tank for ick just in case please?

No, if it has been there consistently and hasn't spread in weeks it is unlikely to be whitespot.
Could you clarify the readings on your test strips and ammonia tests in numbers please?
Fresh water is always helpful so do a large water change (50-75%).
Hopefully someone will be able to identify the spot soon.
All the best.

What other fish are in with her. She may been nipped or it could just be pigmentation. I don’t think it’s anything to worry about. Just keep an eye on it. That Momma should be giving birth anytime now. Congrats and good luck!

Hi and welcome to the forum

It is not whitespot (Ichthyophthirius) and you do not have to add any chemicals.

Whitespot parasites drop off the fish after a few days and divide in the substrate, then they attack the fish in the tank and cover them in spots. If the spot has been there for more than 1 week and no new spots have appeared, it is not whitespot.

I would monitor it and see if it changes. It could be a tumour or Lymphocystis, neither of which can be treated.

Do a 75% water change and gravel clean the substrate every day for a week and see how it goes. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Thank you for the replies, we really appreciate it.

We did a gravel clean / water change this morning, about 70%.

I don't the have figures from the last lot of test strips. Today I tested the water before we put it into the tank so that I could show you the testing strips. Tomorrow I will test the tank water.

I think there is a problem with our ammonia test strips?? The water put in the tank today I think reads 3. They have never recorded lower than that. I asked around our neighbours and someone experienced with fish kindly used their proper testing kit on the tap water and confirmed it was good and different to what our testing strip showed.

First picture below is the Tetra ammonia test, reading 3? but possibly not working correctly.

Second and third is the Tetra 6 in 1 testing strip which I think reads as follows:
NO3 0 (mg/l)
NO2 0 (mg/l)
GH 8
KH 15
pH 7.2
Cl2 0 (mg/l)

Deanasue
Tank has 4 adult platies and 8 fry which are nearly 4 weeks old. We first bought two adults females and didn't know one was already pregnant! They were born on 10th Sept so are expecting the second lot of fry very soon.

I should have said, we used tap safe in the water in accordance with the instructions.

Thanks, your water quality is good. I would throw away the faulty ammonia test.

This is not related to the white spot but just to note, your water composition is not hard enough for platys. The test strips are misleading with their "ok" ranges on pH GH and kh, they probably refer to most (soft water) fish. Your GH is 8 and platys need 14-30dH. You could consider adding crushed coral or limestone to the tank to increase the hardness of the water.

http://www.seriouslyfish.com/species/xiphophorus-variatus/

Thank you for replying Naughts! Thats really helpful.

A closer picture of Toffee. Unfortunately the spot is on the other side of her tail.

Just monitor it over the next few weeks and post pics if it changes. It could be a calcium deposit and might grow slowly over a year, or something else. I wouldn't worry too much at this stage.

The spot got very slightly larger and I think another smaller one was forming above.

She had her fry and sadly died a couple of days later.

Sorry to hear that Carebear.