How do you know when Fish are done with meds

[Willie T]

So I have some Discus that turned darker and one had very long stringy poop, so I am medicating them in a Hospital tank with metronidazole, it seems like they are great some days then they are not 🤷‍♂️They are in a 20 gallon, I went ahead and started treatment on the 75 gallon they came from, So my question is when do I know it’s time to put them back in the tank? When they start eating? It’s odd so sometimes the fish is dark then last night he was vibrant then this morning he is back darker again?? The first pic is from last night the next is from this morning 🤷‍♂️🤷‍♂️

[HH Morant]

If they are eating you should be medicating their food. There is a Wattley Discus video (or two) on youtube about feeding food medicated with metronidazole. The articles below address the need to medicate the food and some methods of making medicated food.

12.5. Fish Don’t Drink (aquariumscience.org)

12.7. Making Medicated Food (aquariumscience.org)

 

 

 

[Willie T]

Thanks, yeah, I just have other fish in the 75 so I have to treat the water, I guess I’m just wondering when they can go back into the main tank, it’s like they are dark then at night they are their normal color , moving around, look healthy then in the morning, in the corner again and dark????

[Tihshho]

The other thing too is the fish are near a window, so if there is a ton of light they might lighten up their color. Fish are generally pretty good (if able) to modify their colors for camoflage as well as to show signs of stress/mood.

[nabokovfan87]

On 4/18/2022 at 7:12 PM, Willie T said:

I guess I’m just wondering when they can go back into the main tank, it’s like they are dark then at night they are their normal color , moving around, look healthy then in the morning, in the corner again and dark????

Coloration varies hour to hour sometimes. I've had some barbs that are very feint, but depending what time of day they settle down and color up. Lights also cause the fish to color up. coloration requires energy, and so a fish that is stressed looks subdued.  One with color is a good sign 🙂 

I would follow the box itself and the directions for meds and how long to medicate. I would not go by coloration.

That being said, it doesn't answer the question of "when do you know it's safe to add them back to the tank.

I would..... treat them with meds (usually a week, sometimes longer), monitor for one week. Then decide.