Fish do a stringy white poop for several reasons.
1) Internal Bacterial Infections causes the fish to stop eating, swell up like a balloon, breath heavily at the surface or near a filter outlet, do stringy white poop, and die within 24-48 hours of showing these symptoms. This cannot normally be cured because massive internal organ failure has already occurred.
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2) Internal Protozoan Infections cause the fish to lose weight rapidly (over a week or two), fish continues to eat and swim around but not as much as normal, does stringy white poop. If not treated the fish dies a week or so after these symptoms appear. Metronidazole normally works well for this.
There is a medication (API General Cure) that contains Praziquantel and Metronidazole.
It's interesting that API and the Californian government have listed Metronidazole as a carcinogen. That's a concern considering it was widely used to treat intestinal infections in people.
Anyway, if you use this or any medication, handle with care, don't inhale the medication, and wash hands with soapy water after treating the fish or working in the tank.
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3) Intestinal Worms like tapeworm and threadworms cause the fish to lose weight, continue eating and swimming normally, and do a stringy white poop. Fish can do this for months and not be too badly affected. In some cases, fish with a bad worm infestation will actually gain weight and get fat and look like a pregnant guppy. This is due to the huge number of worms inside the fish.
Livebearers like guppies, mollies, swordtails & platies are regularly infected with gill flukes and intestinal worms. If the fish are still eating well, then worms is the most likely cause.
You can use Praziquantel to treat tapeworm and gill flukes. And Levamisole to treat thread/ round worms. If you can't find these medications, look for Flubendazole, which treats both lots of worms.
Remove carbon from filters before treatment and increase aeration/ surface turbulence to maximise oxygen levels in the water.
You treat the fish once a week for 4 weeks. The first treatment will kill any worms in the fish. The second, third and forth treatments kill any baby worms that hatch from eggs inside the fish's digestive tract.
Treat every fish tank in the house at the same time to prevent cross contamination.
You do a 75% water change and complete gravel clean 24-48 hours after treatment. Clean the filter 24 hours after treatment too.
Do not use the 2 medications together. If you want to treat both medications in a short space of time, use Praziquantel on day one. Do a 75% water change and gravel clean the substrate on day 2 & 3. Treat the tank with Levamisole on day 4 and do a 75% water change and gravel clean on day 5, 6 & 7 and then start with Praziquantel again on day 8.
The water changes will remove most of the medication so you don't overdose the fish the next time you treat them. The gravel cleaning will suck out any worms and eggs that have been expelled by the fish. Repeating the treatment for 3-4 doses at weekly intervals will kill any worms that hatch from eggs. At the end of the treatment you will have healthier fish.
Ive attached a lot of pictures of the guppies (and one Platty) in the quarantine tank. The healthy fish are in there because when I first began quarantining the fish, I noticed only my guppies were showing symptoms of fin rot, since I have shrimp in my main tank I wanted to treat with salt and kanaplex (I’m currently only treating with salt). The Platty was showing possible signs so I didn’t want to take the chance and moved him to the quarantine tank, however him along with some of my guppies are currently looking perfectly healthy. The weird part about this entire situation is each guppy has a different symptom. I’ll go over each of them.
So I’ll start by saying the two newest fish, guppies a male and female, the ones that died, I bought them from a pet store and their tanks didn’t look the best. I shouldn’t have bought them as my sister warned me that their fish aren’t well taken care of, but I wasn’t thinking straight and bought them. Those two were the ones that died first. The male was first and before he started showing symptoms he seemed extremely healthy, he was one of the bigger guys and swimming around happily. I noticed the day after a water change that he was scratching up against plants, the thermometer and staying completely vertical at the top of the tank, he was lined up in between the thermometer and the tank wall. Since I haven’t had any problems and he appeared before to be one of the most active fish in my tank, I didn’t worry TOO much about it, but I kept it in the back of my head. A couple hours later I found him dead. The female looked fine, aside from a small tear in her fin possibly caused another fish (I’ll admit the tank was a little overcrowded after the two new additions, but my levels were perfect and I kept up with water changes and they appeared to have plenty of swimming room) then within a 24 hour period, she was SEVERELY scratching against plants, gasping for breath at the top of the tank, struggling to swim, red patches appeared inside her, she was pale and wouldn’t eat, and her stomach blew up and she died.
Now, here are the symptoms of the currently living fish.
Orange/Red/Black tailed female:
As you can see, her tail is rotting away very quickly. She has stringy white poop, refuses to eat, either swims at the top of the tank, the bottom, or rests somewhere. She doesn’t swim around a lot. Her top fin I think is clamped and there is a webby/fluffy substance on her left side towards her tail, which is why I thought it was a fungus or bacterial infection. Before all this started happening I thought she was pregnant, as she was beginning to Square up, but she’s a young one so her belly wasn’t giant like some of the older ones are. But one day I thought she had her babies but I never found any baby guppies anywhere. Now it’s difficult for me to tell what’s going on with her as she’s showing so many different symptoms.
The pink tuxedo guppy(Black/blue tail, orange outline and pink body)
He started with just a split in his tail but it’s rotting pretty quickly. Of all my fish, including the betta, he was the most aggressive, but he never chased anybody, he would just give pecks if somebody was in his way and I never noticed him doing any damage. Now, he’s refusing to eat, his stomach appears normal and his tail is rotting away quick. He’s staying at the top of the tank and appears dead but his fins are moving and he is breathing.
The orange and white guppy:
He’s the one with the most pink gills, it’s tough for me to say whether they were there or not before because I didn’t sit down and stare at his gills until now, and he was one of the first guppies to the tank. Other than that he’s healthy
The fanciest guppy with the colorful design and flowy tail:
I don’t know what he’s called, but he is my prettiest guppy. His tail is starting to rot, but other than that he seems healthy.
The other guppies in the tank, the cobra (yellow with black dots), female with a blue and white tail, and fancy guppy with a black/blue/orange faded tail, appear healthy. They are active and swimming around, tails look fine and they’re eating normally, along with the Platty.
The difficult part of this is, I look at the orange tailed female and think it’s Columnaris because of the stringy/fluffy stuff on her back, and then I look at the pink tuxedo mail and think it’s some sort of infection... but then I look at the pretty guy and think it’s just fin rot. One person said I definitely have multiple things going on, however I don’t have multiple quarantine tanks to treat different things. In case this information helps you at all, here are the 4 tanks in the household, biggest to smallest.
50 gallon Cichlid tank, newest tank and my sisters. She just bought a new siphon and equipment to do water changes so my tanks don’t contaminate here’s.
20 gallon random tank, my sisters tank. She has a crayfish in here with some random fish, like tetras, Danios (one of the danios came with the two fish that died, the guy caught him by accident and gave him to us for free so she took him, and all her fish look perfectly fine), a dwarf gourami, and a Platty.
10 gallon planted tank, my original tank. This is where the guppies used to be with the other fish (also shrimp). Since there is shrimp and plants in here, I try not to use treatment because I’ve invested a lot in this tank.
5 gallon Betta/quarantine tank. Normally we use this tank for my sisters betta fish, but when we need a quarantine tank we put the betta in a vase and clean the tank thoroughly before and after quarantine.
Thank you again for all your time and help and I truly appreciate it!
