All Fish In Tank Dead

[Queen Bee]

Help. I have no idea what has happened here. All fish in my tank are dead.

Wednesday my yellow mystery snail died.( It had been in the tank for 6 days) Thursday I did my weekly 25% water change as usual. Friday morning I fed the fish and left for the weekend. Sunday at noon, arrived home and all fish were dead. They had some kind of white stuff on parts of them and the surrounding rocks. The only way I know to describe it is like kleenex after being shredded in water. The water and apartment smell pretty bad.

Tank info

Been running the tank for 2 months. It held 2 guppies and 1 sword tail ( they have been in the tank for 2 to 3 weeks) All water tests were normal when I tested on Thursday. It is a 10 gallon with heater, filter, and air sponge filter.

I am in the process of cleaning the tank and rocks. I am going to sterilize everything and let it dry out for a week. Then I am going to fill it with new water and let it run empty again to start a new cycle.

Is this the right thing to do? Anybody have any idea of what happened to the tank? Do snails give off poisons when they die that will kill the fish?

 

[Corleone]

Snails can decay pretty quickly when they die, and give off a lot of ammonia in the process. You might have had an ammonia spike from the snail. Snails themselves are pretty sensitive to ammonia. You mentioned in another post that you did get some low ammonia readings occasionally (or am I confusing you with somebody else again?). If so, the biofilter may not have been able to keep up with the added ammonia when it died. I had a big snail cause a small ammonia spike in a 55 gallon tank, so they do foul the water pretty quickly, even a well matured filter can fall behind if you don't find the snail right away (mine might have been dead for two days before I found it)

 

[Queen Bee]

Yes, it's me. You're not confusing with someone else.

The snail may have died the night before. He wasn't moving and I thought it may have been sleeping. I checked the next morning and promptly pulled it out.

Ammonia sounds more probable than bacteria. I don't know of any bacteria that kill fish so quickly without any signs. I really don't want to cycle the tank from new again.

 

[Corleone]

It won't be a matter of restarting the cycle. Ammonia spikes just mean the bacteria couldn't keep up for a time, not that they're gone entirely. Just removing the source of the ammonia should fix it, worst case scenario a minicycle calling for a couple water changes.

Edit: Minor correction: Without fish there may be some dieoff in the filter, but if you have ammonia from fishless cycling around, you can sustain the biofilter indefinitely that way until you can get the fish. Failing that, a cocktail shrimp wrapped in nylon stockings will start to rot and give off ammonia. It'll smell a bit, but it'll help sustain the filter and keep you from needing to re cycle for new fish.

 

[Queen Bee]

I want to test my ammonia now to see where it is. I am just worried that there might have been something else in the tank that killed them.

Problem: I put in waste control liquid when I got home and found the fish. I thought it might help break down what ever was in there. Will that put my ammonia test out of wack??

 

[Colin_T]

You might have had a power failure that knocked the fish about and when one fish dies it can cause an ammonia reading, which can kill everything in the tank. The white stuff on the bottom was probably fungus growing on the dead fish and rotting food.
If you wash the tank out you will wipe out the filter bacteria and have to cycle the tank again. You are better off draining the tank and refilling it with dechlorinated water. Then check the water chemistry for ammonia, nitrite, nitrate & PH and if they are ok then add a couple of fish. If the filter has not fully developed yet then perhaps finish the cycling process with some liquid ammonia.

 

[Queen Bee]

Just tested the ammonia. Reading is at 1

Don't know about power failure. No clocks flashing.

 

[Colin_T]

an ammonia reading of 1ppm is toxic and will rapidly kill everything in the tank if the PH is above 7.0. The higher the PH the more toxic the ammonia is.
Having said that the reading is probably form the dead fish.

 

[Miss Wiggle]

oh how sad, if you've had ammonia problems with fish in then i'd say the tank wasn't fully cycled (did you cycle with fish or fishlessly?). I'd suggest before contemplating more fish you ensure the tank is fully cycled, so get some liquid ammonia and go through the usual fishless cycling process (link in my sig if you haven't done this before), however this shouldn't take 4-6 weeks as normal as you already have some good bacteria so it may take a week or so but hopefully not too long. It is important to start this fairly promptly, the bacteria in the filter will start to die off after 12 hrs with no food (although it would take a day or two before it completely die's off).

 

[Queen Bee]

Thanks for all the help. Now I'm pretty confident in what I need to do now.