# Mysterious killer



## RaidZero (Jun 15, 2008)

Hello,

Long story here. TLDR: something is killing my fish in a new tank, and it's not ammonia or nitrites.

First, I am not exactly a newbie. I started having tanks in 2005, at some point I had 6 tanks from 10 to 55 gallons, but in the last few years I only kept two 55s, and now one. 

At the beginning of December, I got a new 5 gallon tank with an integrated filter and light, plus a 25W heater (very basic heater, my mistake) that is supposed to keep the water at 25 C, plus a few artificial decorations. Same day I also bought a betta male and two live plants.

I set up the tank at home with some gravel, water and filter media from the 55, to be sure I get the good bacteria. A week goes by and I feel the tank is bare, the betta is fine, active, eating well. So I go and buy 6 cardinals.

For Boxing Day I go out and get a bag of Fluorite and a couple more live plants. I put a nice layer of Fluorite in the tank, after washing it and washing it. I still had some cloudy water in the tank for a few hours and the filter foam is red from the clay particles, but I have no worries at that time. I wash the filter and all is good for a few days.

I also order two aquarium thermometers from Amazon at this time.

I do 25% weekly water changes, the fishes seem fine, eating and just being themselves. At the beginning of January, the cold wave hits us and the room temperature drops one day to 17, but I am not too concerned because I have a heater, right? The next day I see white spots on the cardinals, and they are swimming together shivering like they are cold. I feel the water and it seems much colder than my 55, which stays at a constant 26 C. The betta seems fine, active and eating.

I thought darn my fishes have ich. Internet at the rescue: best remedy, raise the temp to 30. My puny heater will never go over 25, so I do a 50% water change with warmer water. I place another Amazon order, this time for a nice Eheim Jager 50W heater and an API master test kit. Very busy with a project at work, no time to run around for fish supplies.

Next day, the same routine, I change the water with warmer water, it seemed cold to me. Next morning, disaster. Three dead cardinals, the other three are not eating and looking miserable, and the betta seems not as active as before, but still eating. In the evening I get the package with the heater, I set it up for 30 C and in the tank it goes. 

Too late, in the morning the other three cardinals are gone. I tone down the temp to 26 on the heater, but the next day the betta is gone. 
I finally receive the thermometers and the test kit. The temperature is really 26, I have 0 ammonia and nitrites, between 10 and 20 nitrates. One of the plants must have had snail eggs, cause I see a few snails.

Fast forward a couple of weeks. I was testing the water every few days, same results: no ammonia or nitrites, few nitrates. Snails keep growing and I see very small ones. So on Sunday we decide to get another betta, thinking that probably the temperature changes shocked the previous one. 

It seems to be fine for a day, then yesterday morning it starts to hide. This morning it was gone... I do another full test this evening. Again, same water parameters, temperature is still at 26. 

So what is killing my fishes? I really don't want to look at a fishless tank...


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## RaidZero (Jun 15, 2008)

A few more details: I use Prime every time I change the water (different bottle than the one I have for the 55, which I bought a couple years ago) and since end of December I added once a week a few drops of Flourish Excel for the plants.


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## Wiccandove (May 19, 2012)

can you post a full water test reading before changing your water? ammonia, nitates, nitrites, PH? You also say a few decorations - what exactly?


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## pnutbutr (Dec 27, 2015)

*I hear ya*

When I started this hobby last year it was because my wife came home with a Betta in a small 1 gal tank and gave it to me as a present. Long story short we now have a 10 gal tank, two 2.5 gal, and my display tank of 60 gal. 

However I almost gave up trying to have fish because every single one I put in the 10 gal tank died within 3 weeks. I cycled the way I was told, and read about. I tested and changed the water, but still the Ich came along and I lost everyone. Not only that but some died the next day for no reason at all that I knew of. Recently in my 60 gal tank I added 3 Albino Tetras. They were doing fine along with all the other fish for about a week and then all three died. That along with the 9 Neons I added the same day. We have very hard water here in Fergus but I have added Peat to the filter, and always add the water conditioner.
Ph is at about 7.5 to 8.0

I have to this day no idea why so many of my fish look great one day, and the next they're dead. If you ever find an answer please post it.

Jim


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## Grey Legion (Mar 20, 2006)

Being that your tank is only 5G changes in the water will be FAST. So this can be a factor, tempature is always to be monitored and never fully trust the thermostat in any heater (good your have thermometers). It really sounds you are trying all the right things, the only thing I can say is get rid of the snails ASAP, while they look "cool" now they will be a problem in the very near future.

Eggs came on plants for sure, look up how to dip your plants to kill of snails etc.

best of luck and keep the forum posted on your progress.


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## solarz (Aug 31, 2010)

6 cardinals and 1 betta in a 5G tank is a very high bioload. I would suggest going with some cherry shrimps instead.


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