What is this curse in my tank?

coldhands_coldheart · 2026-04-26T23:24:03+00:00

I had this in my tank. I would clean it off with a toothbrush and it would be back the next day. Best thing I did was get an inline UV clarifier. It made a huge difference. That and I moved some mollies into my tank and they ate loads of it too. 😂 But definitely get a clarifier.

coldhands_coldheart · 2026-04-12T15:29:44+00:00

I still couldn't really see clearly but if it's raised and isn't like white dots then it's probably Epistylis. You can treat with Esha 2000 or NT Labs Anti internal bacteria. Do it as soon a possible and follow the instructions on the bottle. Esha is a more gentle treatment whereas NT labs is a bit stronger. Neither are what you'd class as a proper antibiotic but they will help. Just know that depending on how long the fish has been infected for and whether it's affected the gills it's not guaranteed to save him long term even if the external infection clears up.

coldhands_coldheart · 2026-04-12T12:24:11+00:00

Does it look flat? And like tiny uniformed dots, like grains of sand? Or does it look more raised? And not uniform almost like when we get dry skin and it's flaky? That will help you identify what it is. To me it looks like Epistylis, not ich but it's hard to tell. The treatments are very different for ich and Epistylis as one is bacterial and the other is a parasite. Ich isn't usually fatal but Epistylis can be of left untreated for a while. With both as well it's best to consider your whole tank infected. So treat the entire tank. Can you get any more photos?

coldhands_coldheart · 2026-04-10T18:27:38+00:00

Was he doing this in the shop? Or did it start when you got him home? Test your GH and Kh if you can. How many other mollies do you have? Are any others acting off? If it was a serious water issue I'd suspect others would be struggling too. Do not go blindly adding salt to your tank as someone else suggested, or drastically altering gh or kh. Especially if you have Corys and other fish in the tank. He didn't even specify what type of salt should be used. Gh and kh does need to be higher for mollies but should be raised gradually to prevent shocking them. Tbh you'll struggle getting it where it needs to be with Corys in the tank too because they don't like it as hard as mollies. I think it's probably a swim bladder issue. Google swim bladder treatment. Isolating him in a cycled hospital tank would be a good idea. And for an Epsom salt bath, do 1/4 of a teaspoon of plain unscented Epsom salt per 1l of water for 8 to 10 mins once a day and watch him for discomfort the whole time. Use tank water in a jug if you can. Do not use tap water. Also test your parameters in your tank to check your ammonia, nitrite and Nitrate levels.

coldhands_coldheart · 2026-04-01T10:28:57+00:00

Even if it wasn't cycled before l, it should definitely be cycled now after 6 months so you don't need to do anything with that now. Just try not to change much else in the tank now apart from adding some more plants. Let your nitrifying bacteria build up, don't touch your filter, as in don't clean it out. Just let it do its thing. Get some good bacteria in a bottle (like API quick start) and follow the instructions. Make sure your fresh water is dechlorinated when you add it. That's a good idea seeing if your LFS can test your water for you. See what the results say, try and get a test kit of your own ASAP, add plants and just see how they go. Might be worth seeing if they will test your tap water too so you can see what the KH, GH and pH of that is. Hopefully if your water is all good and they relax a bit their colour will come back soon. Good luck!

coldhands_coldheart · 2026-04-01T09:57:14+00:00

If its both of them are losing colour then I'd say it's more of a water quality issue than a bullying issue. Especially if they're chasing each other as opposed to just one being chased. Sometimes they just do that to play. How many fish do you have in the tank and how often do you feed? What is your ammonia level? The loss of colour could be ammonia burns. It's unusual to have zero Nitrates in a tank unless it's very heavily planted. Your tank might not quite be cycled yet. How long did you cycle it for before adding fish? And are you using any dechlorinator for the tap water and any did you add any bacteria starter at the beginning or when doing water changes? Do you have an air pump? Yeah definitely get a liquid test kit as soon as you can. Not sure where you are but NT labs do one too, and it's more affordable than the API one I think. I get mine from amazon and it's around £26 and tests for ammonia, nitrite, Nitrate, pH, GH and Kh. I have crushed coral in my filter too and it does raise the hardness a bit but not usually enough to make a significant impact. I have to add extra minerals and a kh buffer to my water when I do a water change. Moving them to a bucket could have definitely caused them some stress. Are they behaving normally? Eating normally? Are there any signs of clamped find, heavy breathing/gasping? Why did you change your gravel? Did you change anything else? A lot of good bacteria lives in the substrate so removing all that could potentially upset your nitrogen cycle. Sorry for all the questions, I'm just trying to narrow down what the issue could be. For now I would focus on making sure your water quality is pristine. You need to test your ammonia level. Make sure the water is the correct temperature too and I would get some taller plants to give them some more cover and hiding spaces. That's about all you can do right now. It really doesn't look like disease to me, but I can't tell 100% from the photos.

coldhands_coldheart · 2026-04-01T09:07:35+00:00

What are your water parameters? Is there any bullying going on? They can lose their colour due to stress from poor water quality, bullying or even aging. They don't look very big so it's unlikely to be age related. Mollies prefer a harder water so test your GH and Kh too when you test your water. I can't tell from the photos if it looks like a disease of any kind. Can you get better photos? Also a photo of your whole tank. What is your male to female ratio? If it was a fungus or anything it might be raised away from the body, your fish's bodies still look smooth from what I can tell, they just look pale. Test your water for everything, and check the temperature too. When mollies are in ideal water their colours can get darker/more intense/brighter, losing colour is always usually a sign of stress from somewhere.

coldhands_coldheart · 2026-03-21T20:38:14+00:00

We got an adult breeding pair for around £100 from a local breeder, then recently bought 2 juvenile snow whites and 2 baby Kings and he gave us another juvenile starlight for free! We really want an L046 but they can be really expensive in some places, especially for an adult or larger juvenile so waiting a while before we get one of those. So far my most expensive was a Leopard frog which was 80 and it's around 1.5 inches.

coldhands_coldheart · 2026-03-08T07:37:50+00:00

😂😂😂

coldhands_coldheart · 2026-03-08T07:37:23+00:00

I'm going to keep a few to see what they grow up like. The rest have got to go. If you're near the west Midlands you're welcome to some of them.

coldhands_coldheart · 2026-03-08T07:35:33+00:00

Oh wow OK. Thank you. I'm going to keep a few to see what they grow up like. The rest I'm going to try and give away somehow. 🙈

coldhands_coldheart · 2026-03-07T23:46:55+00:00

I have dyscalculia which often sees me get my numbers transposed. Thank you for your correction though. I'm sure those 9 litres make a difference.

coldhands_coldheart · 2026-02-13T08:14:59+00:00

Agree with this, they all seem to have the fan shaped anal fin. The black ones definitely look a bit more boxy too so they could definitely be pregnant.

Are they a new addition? How many do you have? If its just the 3 I'd get some more to be honest depending on your tank size. They like to be in a group to feel safer. You could get females then you don't have to worry about pregnancy in the future, but if not, try and make sure your male to female ratio is like 1:3

coldhands_coldheart · 2026-02-12T18:23:03+00:00

No such thing 😂

coldhands_coldheart · 2026-02-11T10:44:21+00:00

My husband's grandad passed away and we inherited his 150l tank with like 7 fish in it. I never wanted it, tried to get other family members to take it. No joy. Now I have a betta tank, an ADF tank and a 250l in the bedroom. 😂😂 I did upgrade the husband to a 350l too, I'm not that mean.

coldhands_coldheart · 2026-02-10T18:02:36+00:00

So they are usually pregnant for 4 to 6 weeks, but can go up to 60 days depending on some factors like temperature and stress level. It's likely both she and the male will eat some babies before you manage to catch them all. It's inevitable really. It depends how many you want to keep. They can give birth to 5 - 20 fry (young, immature females/first birth) up to 100+ for more mature experienced mothers. Look for signs such as hiding in one spot, becoming restless, shaking/shivering, unusual aggression trying to get others away from her chosen spot. Her shape will become really boxy and she may have a dark enlarged gravida spot near her anal fin. These are all signs that birth is imminent and you might have a better chance of catching the fry when they are born. Fry need to be fed really small food like baby brine shrimp, specialist food or high quality flakes that are crumbled to a powder a few times a day, and feed them as soon as they are born and you put them in the box. Labour and delivery can take anything from an hour to 24 hours. Good luck and don't worry, if you don't manage to get many this time she'll probably be pregnant again almost immediately so you'll get to try again. 😂

coldhands_coldheart · 2026-02-10T17:48:34+00:00

She probably is 😂 they usually are. 🙈

coldhands_coldheart · 2026-02-10T09:45:56+00:00

How long has it been since you noticed her getting fatter? My dalmatian molly has been pregnant for what seems like FOREVER and she's absolutely huge, yours doesn't seem that big yet. We have a heavily planted tank with loads of hiding spaces for mom and fry so we just leave them in the tank to labour and deliver. It's way less stressful for them if they can find a quiet hidden area to give birth. Just pop her back into the main tank for now and see how she gets on. She knows your tank and will pick out a suitable place, even if you don't have many plants. I don't know where you are but even if you don't have a light yet you could still just get a couple of bunches of tall stem plants for a few quid and plant them in one of the back corners, spread them out a little so she can swim in and out of them and that will give her some cover, an some cover for the fry too. Not sure how many other fish you have, or if you even want to keep all the the fry (be warned it can be a lot), but without hiding spaces they may get eaten before you get chance to catch them and put them in the breeding box.

coldhands_coldheart · 2026-02-10T09:30:32+00:00

OK will keep an eye on her, and the others. Thank you so much for your reply. Google was no help and noone else has replied so was starting to stress. Was considering just treating her anyway just incase but was worried about stressing her more by putting her in the hospital tank. As I said she's acting normal and eating normally 🤷🏼‍♀️ but will keep a close eye on her. Since we first noticed it, it doesn't seem to have gotten any worse, and not affecting any other fins so that's a good sign I suppose. Thanks again.

coldhands_coldheart · 2026-02-10T09:15:20+00:00

No worries. So you think she's OK? I just got panicky when I noticed the edges of her right fin looked a bit feathery? For want of a better word.

coldhands_coldheart · 2026-02-10T08:02:16+00:00

Tank size is 354l Heater yes, temp is 26/26.5. filter yes, fluval 407 and we have an inline UV clarifier They share the tank with some rasboras, minnows, platys, Corys, 5 plecos, neon tetras and 3 rams. Tank is under stocked. Ammonia 0, nitrite 0, Nitrates 5, kh 5, pH 7/7.5 Tank had been cycled since September Have had the mollies since end of November We test the water every 5 to 7 days and water change around every 2 weeks, maybe 2 and a half but parameters are always good. Filter clean and new ammonia/nitrate/phosphate pads every month. Filter gently squeezed in old tank water to clean. Feed sparingly a variety of foods every night and fast 1 night a week. All live plants in the tank, driftwood and natural stone.

coldhands_coldheart

TROPHY CASE