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Nov 28, 2015
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Hi, I have a 75litre freshwater aquarium, water conditions normal on test strips and water is conditioned(been having a misty water issue but it is improving), carbon integrated filters and heated of course. (1/4 water change - 2 days ago)

3 male mollies, 9 female mollies, 3 molly fry, 1 female swordtail, Pleco and Snail, all of which were given to me as babies, now adults with exception to the fry.

Something is killing my fish at a 1 fish a day rate - i notice a pale circular lump on their bodies and in less than 1 hour they are swimming vertically and by the next day they're dead, half eaten and covered in pink worms, i've also noted fast pooping and some clear poops. I've also had white hair like worms crawling up the glass since my tank was set up for me.

I am trying to find out the main issue so i can treat it before i have an empty tank and heart attack.
I consider myself a severe beginner.
Attached image the BEST I can take, please note lump at centre of fish. Fsh.jpg
Hi and welcome. Let's see if we can get you sorted :)
Firstly I havn't got a clue what these pink worms are but the ones on the glass could be something called 'planaria' which can turn up in new set up. Are they very very small? 
I suspect this is an ammonia issue but to be sure we'll need some more information. That way we can help you appropriately.
So we know it's 75 litres and that you use strips to test the water. The first thing I would do is to go and buy a liquid drop test kit as the strips are notorious for being very inaccurate. API do a good beginners kit and it's easy to get hold of. It's the API Masterkit. It contains all you will need - pH, ammonia, nitrite and nitrate. It also comes with test tubes and card reader. I see you are in the U.K and so you should be able to get a kit from Pets@Home or any good aquarium shop.
How long has the tank been running and how often have you been changing water and how much? Do you use dechlorinator when you water change? How have you been cleaning the filter? 
Next the misty water ... this sounds like a bacterial bloom and again, is common in new set ups. It can be cleared with large water changes but it often settles on it's own. 
So, once you have a liquid drop test test the tank for all four things and let us know what the readings are. 
In the meantime I'll tell you to always remove dead fish immediately. Never allow the tanks occupants to eat a dead fish. If the fish has died from disease it only spreads the disease. 
I would also suggest doing daily water changes until we know the tank water readings from the kit. If you change 50% daily you won't do any harm. If this is an ammonia issue (or a nitrite issue) it will reduce it.
As said above - I don't know what the pink worms are - I've never come across that before but someone else on here may have and may be able to advise you better. The lump on the fishes side could be an ammonia burn or it could be something else. It's difficult to tell from the photo.
Hopefully I've been some help :)
Hi, i've had the tank since June this year, i was cleaning my filter in ordinary tap water until a few weeks ago when i was told to use same water as the tank(put in a bucket, of course)

I don't know much about chlorine but I've used the API tap water conditioner since day 1 and occasional freshwater tonic salts since i've heard it would help my water.

Water changes used to occur randomly but now are 1/4 weekly but I will be taking your advice on all matters here

As for the dead fish, I found it in the morning already eaten, I do try but it seems most deaths occur at night in this tank.

Getting information on tropical fish from the guy who gave them to me has been like pulling teeth, most recent info has come from older pet shop in town that also pointed me here.

API test kit has been ordered :)
I will let you know the results as soon i get the kit
great stuff.
Always use old tank water to clean sponges and do water changes of at least 25% weekly if you can - that is once we get you sorted. For now stick with the larger 50%
Glad you are using dechlor, API is a good brand. I don't know what the tonic is but it sounds like a gimmick. I'd knock that off until we get you sorted with what's going on. All the fish need is a cycling filter, clean water and good quality food. 
What I'm gonna do is point you in the direction of the beginner section and the cycling the tank info. Apologies if you've already found it and read it. If not I think it'll help you to get a grasp on things and the reasons why I'm suggesting what I am :)
Have a read here http://www.fishforums.net/index.php?/forum/291-cycle-your-tank/ if you read the pinned posts there you should be able to digest some good info :)
not a problem, that's what we're here for 
Could be ammonia, but I'd be more concerned about these pink worms. If you google internal parasite some of the images are of worms, ranging from white to red. Camallanus nematodes are nasty little things.
Hi Munroco, I've looked up the parasite and can't note ever seeing the worms protruding from the anus of any of my fish (not ruling it out) I have payed attention to the fact that when the tiny (3mm - 20mm) hair like worms are wiped off my tank glass they change colour from white to pink.

I'm not an expert in any way with my tropicals and don't even class myself as a stable beginner, If the worms are camallanus and do indeed need levamisole (this stuff is harder to get than genuine fairy dust unless you buy the bird meds... :/) i think my fish would end up dying first

I'll attach an image of the worms on the tank.

Also - my female is still alive.


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I wouldn't dose for worms unless I was sure thats what it was, I was just throwing a possibility in for opinions. I hope it isn't camallanus

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