40+ Guppies dead over 3 days

[Fishrookie12]

Hi guys, thanks for reading. I have lost 40+ guppies in the past days.

Tank size: 90L
pH:7.6
ammonia: 0
nitrite: 0
nitrate: <10ppm
kH: N/A
gH: N/A
tank temp: 28 degrees celsius

Fish Symptoms (include full description including lesion, color, location, fish behavior):
There was various symptoms. Most fish had clamped fins, they'd swim against the current and scratch against against plants. Before they die, they generally go to the bottom of the tank, breathing heavily and struggling to swim. A lot of then had cloudy fins a lot like fin rot with cloudy dots on top of their heads. Their bodies had red spot on the bottom of their belly and for some reason, their belly had a hole in them after they die and always belly up.


Volume and Frequency of water changes: 50% water change twice a week

Chemical Additives or Media in your tank: Added melafix as a treatment

Tank inhabitants: Guppies, Bloody Mary Cherry Shrimp and Pond Snails

Recent additions to your tank (living or decoration):
I added 10 dumbo ear guppies (5 of which died the day after i got) - I suspect this was the source.

Exposure to chemicals:

Digital photo (include if possible):

 

[Lunar Jetman]

The most obvious thing I'd say from the information you've given is that the temperature of your tank is near the limit of what i'd keep guppies at. In fact I'd lower that to around 23-24 degrees straight away as i prefer to keep guppies at a temperature lower than 28 degrees.

Are the shrimps all ok? They tend to be much more sensitive to water parameters than fish so if they're ok i'd lean towards something the new fish brought in or the temperature is too high.

 

[Fishrookie12]

Shrimp is all fine (surprisingly at 28 degrees celsius), no death or casualty. Even baby shrimp which is more sensitive is doing perfectly fine. I initially thought they had ich, so I lifted the temperature. Yea, it is mmost likely to the new fish. I've got 10 remaining in a separate tank, hoping that they havent contracted the disease. Do you have any advice for these 10 that I have left? They're in a massive 200L tank

 

[Colin_T]

Hi and welcome to the forum

The fish have a bacterial and protozoan infection. The protozoans are irritating the fish and causing them to rub on objects in the tank. The bacteria is eating away the skin and possibly causing the red sore on the belly abdomen area. However, that could also be caused by another fish in the tank.

What other fish are in the tank besides the guppies and shrimp?

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Melafix won't help with this. If you only have guppies and shrimp you can add salt and a broad spectrum fish medication that treats bacteria, fungus and protozoan infections.

You can use rock salt (aquarium salt), sea salt or swimming pool salt at a dose of 2 heaped tablespoons of salt per 20 litres of water. In addition to the salt I would add a broad spectrum fish medication.

With medications make sure they are safe for invertebrates like shrimp. Otherwise move the shrimp into a separate tank during treatment.

To work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

When you measure the height, measure from the top of the substrate to the top of the water level.

There is a calculator/ converter in the "How To Tips" at the top of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating or it will absorb the medication and stop it working.

Wipe the inside of the glass down, do a 75% water change and complete gravel clean. And clean the filter before treating.

Increase aeration/ surface turbulence when treating to maximise the oxygen levels in the water.

 

[Fishrookie12]

Hi and thanks Colin for replying. No other fish other than guppies. I've lost pretty much the whole colony, just the remaining 10. Should I remove plants or move them out of the tank? Im worried that the whole tank is contaminated.

 

[Colin_T]

The entire tank and everything in it will be contaminated so there is no point moving plants because they can spread the disease to other tanks.

If you can move the shrimp out then you will have more choice of medications to use on the fish. However, the shrimp will also carry the disease on their bodies and can cross contaminate other tanks so move them into their own tank if possible. Otherwise leave the shrimp with the fish and treat as is.

If you can separate the shrimp, keep them separated from fish for a month and hopefully any parasites that got moved across with the shrimp, will have died without a fish host. Most fish parasites do not affect shrimp and the parasites die after a few days to a week or so without a fish to infect. By keeping the shrimp separated from the fish for a month you should be able to get rid of the disease from the shrimp.

 

[Fishrookie12]

Right, wouldn't the salt kill plants tho? Perhaps I should move the fish out and leave the tank with the shrimp in it for a month instead?

 

[Colin_T]

2 heaped tablespoons of salt per 20 litres of water will not affect plants or filter bacteria.

If you have a smaller tank then you can move the guppies into it and treat them there. You will require less medication in the smaller tank so it will reduce the cost.

If you move the fish out of the big tank, do a 90% water change and gravel clean each day for a week to help dilute the pathogens in the water, then let it run for a month before adding a couple of fish. See how the new fish go for a few weeks and if there's no issues, then add more fish.

While protozoans will die after a few days without a host, bacteria can live in the tank for a while so water changes and gravel cleans should help to remove most of them and hopefully any left over will die without a host.

 

[Fishrookie12]

How long should I leave them in the salt bath for? Should I treat the broad spectrum medication and salt separately?

 

[Colin_T]

The salt should be added to the aquarium and kept there for at least 2 weeks after the fish have stopped dying and everyone is good. Basically you are adding salt to the tank and keeping the fish in a brackish (slightly salty) water for a minimum of 2 weeks.

In bad cases like this you add salt to the tank and add medication too.

 

[Fishrookie12]

Is regular rock salt fine? I got the SAXA natural rock salt made from evaporated sea salt.

 

[Colin_T]

Rock salt, aquarium salt, sea salt or swimming pool salt are all suitable.

Do not use salt with iodine in (basically don't use table salt that is fine). The stuff you have is fine to use.

 

[Fishrookie12]

Ok thanks so much for your help! Which broad spectrum medication would you recommend? Blue planet multi-cure?

 

[Colin_T]

Blue Planet multi cure will be fine. It has Methylene Blue that will wipe out the filter bacteria and stain the silicon blue but it is quite safe and kills fungus and bacteria. It also has Malachite Green in and that will kill any protozoans.

Malachite Green is carcinogenic so wash your hands and arms with warm soapy water after working in the tank.

Keep the medication away from children and animals.

 

[Fishrookie12]

Good news! One of the females I had remaining just released 20+ fry. If the methylene blue kills the filter bacteria, would the bank become uncycled? I've decided to do the treatments in the tanks just to make sure nothing remains. Do I need to be doing water changes during the treatment?