“Disinfect” Tank w/Fish In It?

[FranM]

I have an 120 gallon five years running. Two Fluval 407. Temp 82. Nitrate 10. Ph 7.4. GH—3. KH 2-3

4 clown loaches varied sizes (oldest is 10 years)

3 Yo-yo loaches (oldest is 4 years)

1 lingering silver dollar ( 13 years old)

Over the course of a year I started losing silver dollars to bloat/possibly dropsy and pop-eye. I can tell you truthfully that I do regular water changes. I don’t allow nitrate to go over 25 ppm. I don’t use a hospital tank. I treated the tank with Kanaplex. No improvement. Maracyn. Nothing. Eventually I just lost the fish. Through this all the loaches remained unscathed. However the cherry barbs, that came after the others, have been dropping. I just removed the last one with dropsy tonight.

So my stupid question I guess is if there is a way to “disinfect” the aquarium while fish are in it? Or just let it go? The aquarium is very understocked. When I upgraded to the 120 from a 55 I was reluctant to add fish for a couple years. But then I did—and that was probably when the problems began.

This aquarium needs dither fishes. I considered tiger barbs. Right now I’m fearful of adding anything. A couple questions:

1. Can my tank harbor lingering disease that my fish are immune to but new fish could be affected?

2. Has anyone “disinfected” new fish with a potassium permanganate bath prior to being added to an established aquarium?

3. Does anyone have advice for me?

4. Oh another thing. I’m getting some new algae—a pale red/pink in patches on the glass. Also, I have a lot of diatoms. My tap has 1 ppm of phosphate in it. I don’t have live plants. And the green spot algae is a challenge to remove.

Thank you.
Fran

 

[Colin_T]

Pictures of the algae?

There is no way to truly disinfect an aquarium while there are fish in it. Anything strong enough to kill things will also kill the fish.

There is a possibility the fish have Fish Tuberculosis (TB). This tends to cause internal organ failure and fish bloat up and die randomly over a period of time. There's no cure for it and the tank usually gets stripped, sterilised and started again with new fish.

Loaches and a number of other bottom dwelling species seem to have some resistance to Fish TB (Mycobacteria species), but they eventually die from it too.

If you suspect Fish TB, take a live fish or very recently dead one to a fish vet or fish health lab and have them do a necropsy (animal autopsy) on the fish. Tell them you have concerns about Fish TB and get them to check everything.

The other possibility is there is something else in the tank that is causing the fish to get internal problems (possibly an internal protozoan infection). This can be form a dirty aquarium, lots of gunk in the filter or substrate, or bad / incorrect food for the species.

I assume the silver dollars were fed mostly plant based foods?

Do you use live Tubifex worms or frozen bloodworms?
Both of these foods have been known to cause intestinal problems including internal bacterial and protozoan infections in some fish. Some brands of frozen bloodworms are fine but other brands are bad. If you use frozen bloodworms, try to find a brand that has been irradiated. It sounds bad but it is a safer cleaner form of food.

 

[GaryE]

1. Can my tank harbor lingering disease that my fish are immune to but new fish could be affected?

2. Has anyone “disinfected” new fish with a potassium permanganate bath prior to being added to an established aquarium?

3. Does anyone have advice for me?

4. Oh another thing. I’m getting some new algae—a pale red/pink in patches on the glass. Also, I have a lot of diatoms. My tap has 1 ppm of phosphate in it. I don’t have live plants. And the green spot algae is a challenge to remove.

Thank you.
Fran

1. Yes, but the loaches are doing fine, so probably, the fish carried something in from the store and didn't spread it.

2. Disinfection with potassium permanganate would be a cruel form of euthaniasia. They would be dead quickly.

3. I don't think you are understocked. That's a lot of loaches. They need no dithers. Now, whether you want more fish is the question, but I would hold at what you have. Clown loaches are sensitive fish. If you wish to add, you always take a risk. A QT tank is expensive, but with such nice fish already, consider whether it's worth investing in.

4. I used to get red algae. Cool stuff. It puts up a fight on the glass, but a one sided painter's razor blade will remove it.

 

[FranM]

Thank you to those who replied.

The silver dollars were given a variety of food choices. Sinking veggie wafers, shrimp pellets, romaine lettuce, frozen bloodworms (Hikari), occasional zucchini. So in a nutshell foods are varied.

I am going to attemp a video showing the algae and complete mess. I don’t know if I have lighting issues. Also, I have Phosgaurd in the filter which I haven’t changed since…..according to my logs, Apr 13th. They are probably leeching phosphate back in. The lighting fixture is an LED: Current USA Satellite Freshwater LED Plus Light for Aquarium, 48 to 60-Inch https://a.co/d/dcADyBv

Can I do any type of live plant with this lighting? With many silver dollars I couldn’t do live plants if I wanted to. But now with one…..

Going to attach video now….I don’t think I can. But I can attach photo of algae.

 

[Oblio]

Did you recently change your lighting? Several months ago I changed to LED from fluorescent and I found the default levels caused a fair amount of algae and cyanobacteria. After reprogramming levels and time it is beginning to be under control.

 

[FranM]

This lighting has been in place now since 2018.

 

[FranM]

1. Yes, but the loaches are doing fine, so probably, the fish carried something in from the store and didn't spread it.

2. Disinfection with potassium permanganate would be a cruel form of euthaniasia. They would be dead quickly.

There are YouTube videos regarding potassium permanganate, plus research I have looked up, saying that in a short bath, the p.p. could remove any parasites and kill bacteria. The fish need to be monitored of course. But it can be done with a light dose of p.p. Maybe I will start a new post to see if anyone has successfully tried this method.

 

[itiwhetu]

From my experience Silver Dollars only do well if fed aquatic plants, my fish preferred Water sprite (Indian fern) which they were fed exclusively. Please don't treat your tank with chemicals unless you know exactly what you are trying to cure.

 

[Colin_T]

The red brown algae could be Cyanobacteria or just brown algae. If it wipes off in a film and smells musty/ mouldy, then it's Cyanobacteria (blue green algae). This love nutrients, red light, dry fish food, low oxygen levels and low water movement.

If it's just brown algae (Cyanobacteria is a photosynthetic bacteria not an algae) then you should be able to control it with live plants and reducing the light. However, silver dollars (even just 1 fish) will eat live plants so maybe reduce light.

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Adding poisons like potassium permanganate to a tank with fish in will more than likely kill the fish. Adding it to an aquarium where you don't even know what the disease is just doesn't make sense. You need to find out why the fish are dying and then treat for that disease or problem.

Potassium permanganate does not kill Mycobacteria in fish or in the aquarium.

We need pictures and video of the fish.
We need a full history of the fish and the tank.

 

[FranM]

How do I add video? Save to YouTube and then link?

I just scraped nearly all of the glass algae with a great tool. I have tons of black/brown algae on plastic plants. I attribute that to an overproduction of phosphate. I’ll be glad to give a more in depth history later on today. Packing for a road trip with my daughter.

 

[Oblio]

How do I add video? Save to YouTube and then link?

Yes

 

[FranM]

Yes

I’m away from home for the next several days….