Sick Fish...What should I do??

[TheFishMan2021]

Hi! I have a 30 gallon freshwater tank with about 10 zebra danios, 3 black skirt tetras, and 4 otocinclus catfish. I recently solved a HUGE algae problem in my tank by accident when I went on vacation for 9 days. The lights stayed off 90% of the time and I came home to a beautifully clean tank. From now on, I only turn the lights on for a couple of hours a day. One of my black skirts has always been susceptible to funky diseases and It's got something I can't figure out now. It's head's curvature has been reduces to a point, and the head and gills have odd chalky stuff on them. I've included pictures below so that you can get a better look @Colin_T @Essjay @Fishmanic I'm tagging you guys because I know that you are knowledgeable and may be able to help me. *Also: I don't have parameters but this fish has been in QT for 4 day since I saw the funky stuff on it and I tried to but it back in tonight but want to be really careful and not leave it in overnight if I shouldn't.

I will edit and add pics in a few minutes, plz be patient

 

[TheFishMan2021]

Hi! I have a 30 gallon freshwater tank with about 10 zebra danios, 3 black skirt tetras, and 4 otocinclus catfish. I recently solved a HUGE algae problem in my tank by accident when I went on vacation for 9 days. The lights stayed off 90% of the time and I came home to a beautifully clean tank. From now on, I only turn the lights on for a couple of hours a day. One of my black skirts has always been susceptible to funky diseases and It's got something I can't figure out now. It's head's curvature has been reduces to a point, and the head and gills have odd chalky stuff on them. I've included pictures below so that you can get a better look @Colin_T @Essjay @Fishmanic I'm tagging you guys because I know that you are knowledgeable and may be able to help me. *Also: I don't have parameters but this fish has been in QT for 4 day since I saw the funky stuff on it and I tried to but it back in tonight but want to be really careful and not leave it in overnight if I shouldn't.

I will edit and add pics in a few minutes, plz be patient

Here are the pics:

Here’s some pics of my other tetra for comparison

 

[Dajuyu]

Hows the eating habit ... did it still eat normally ?
Any irregular swimming pattern ?

 

[Colin_T]

It looks like it has a microsporidian infection or an internal protozoan infection, or both.

In the 2nd and 3rd pictures, showing the fish from its side with the flat head, the muscle tissue in the body appears almost a cream/ ivory colour. That is typical of a microsporidian infection.

The same picture also shows a bit of stringy white poop? coming out of its butt. That could be an internal protozoan infection or excess mucous caused by stress.

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Test the water for ammonia, nitrite, nitrate and pH.

Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate. The water change and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

Add some salt, (see directions below).

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

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, Bettas & 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, fish, 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.

 

[Colin_T]

The lights stayed off 90% of the time and I came home to a beautifully clean tank. From now on, I only turn the lights on for a couple of hours a day.

LIGHTING TIMES
Aquarium plants need at least 8 hours of light per day and if you only have the light on for a couple of hours a day, they struggle. If the light doesn't have a high enough wattage they also struggle. Try having the tank lights on for 8-10 hours a day.

If you get lots of green algae then reduce the light by an hour a day and monitor the algae over the next 2 weeks.
If you don't get any green algae on the glass then increase the lighting period by an hour and monitor it.
If you get a small amount of algae then the lighting time is about right.

Some plants will close their leaves up when they have had sufficient light. Ambulia, Hygrophilas and a few others close their top set of leaves first, then the next set and so on down the stem. When you see this happening, wait an hour after the leaves have closed up against the stem and then turn lights off.

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TURNING LIGHTS ON AND OFF
Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly.

In the morning open the curtains or turn the room light on at least 30 minutes (or more) before turning the tank light on. This will reduce the stress on the fish and they won't go from a dark tank to a bright tank instantly.

At night turn the room light on and then turn the tank light off. Wait at least 30 minutes (or more) before turning the room light out. This allows the fish to settle down for the night instead of going from a brightly lit tank to complete darkness instantly.

Try to have the lights on at the same time each day. Use a timer if possible.