Platy staying at bottom of tank

Hi,

I have a 60L tank setup which houses 3 male platies. The tank has cycled and they have been living in the tank for the best part of 3/4 months. I do part water changes weekly and test the parameters using the API test kit.

However, over the last 2-3 days, one of the platies has been hiding at the bottom of the tank. He doesn't seem to be gasping for air or look like anything is wrong with him. The other 2 are still as active as ever.

Any ideas why this is happening?

Thanks,

Brett

What are your current water test results? When was the last water change, and how much do you usually change?

pH is between 7.4 - 7.6. Ammonia - 0ppm, Nitrite - 0ppm, Nitrate - <5ppm. Water was changed yesterday evening as the nitrate level was at about 5ppm; ammonia and nitrites were still at 0ppm. Usually change around 15-20% a week.

Hhmm, not ammonia or nitrites then.
Any chance the tank has been contaminated with anything? Cleaner used near the tank, air freshener, anything new added recently?

If you could get some photos of him, @Colin_T has a great eye for seeing potential problems.

What's your water hardness?

How do the 3 interact - is there much fighting?

Does this happen all day or particular time?

Photo please, A photo is like a thousand words.

Here are some pictures, sorry for poor quality, my phone isn't very good. I tried to take a video as it's like he is swimming lopsided and not a lot of power in his swimming, I'm wondering if he's been attacked by one of the other fish and is injured? I've not seen them go for each other, even around feeding time, but that's not to say it doesn't happen.

The shape is very unusual. @Colin_T does that look normal?

Not normal, the shape is very deformed. Has he always been shaped that way with the hunched back?

Could be an internal problem because of the deformity, deformed fish don't tend to live as long I'm afraid.

It could be a genetic deformity or a disease. Try adding salt to the tank.

You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 2 heaped tablespoon per 20 litres of water.

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 4 heaped tablespoons 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 (4 heaped tablespoons per 20 litres) will affect some plants and some snails. The lower dose rate will not affect plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

That is just an old looking fish

Thats a really strange looking platy it must be old.

Could be an inbred fish. They do that hunchback thing. Platies and mollies also do that when water params are severely outta wack. Water gets bad enough, they will bend into a U shape and die.

These are hardy fish, when you get good ones. They will live well in a well established tank. Your tank is still young, but should be cycled by now. Maybe it just needs places to get away for a.while.

I think the deformity is your first clue. If it wasn't always like that, you need to figure out which water parameter is off. Usually ammonia that does that I have found. Add live plants to help control that and other params. Get some snails and shrimp maybe too, to help keep the substrate cleaner. Food gathering in the rocks will kill fish fast. It may look clean, but, your tank being so young, not enough good guys are breaking.down the stuff that works its way into the bottom. Plants help big time with that. They eat up leftovers, with the help of bacteria breaking it down....