Massive Loss Of Fish

[greyday]

Hi guys
 
Newbi here with a huge problem. Bought my tank six months ago and went completely by the book upon start up. Everything was going perfect until last weekend. I went away for 2 days only to return home to about 16 dead fish!! I had a mixture of guppies, mollies, platys, gouramis and dwarf frogs. One molly, 2 frogs and 2 gouramis were the only survivors when I returned and since then the molly has also died (looked like it had some kinda fuzz all over)? Water was tested by the local aquarium place who said it was next to perfect, also should mention I added one of those feeder puck things before I left and that I do weekly 1/4 water changes (20 gallon tank).
 
Guy at the shop blamed it on the hydro going out and therefore no oxygen but my clock wasn't even flashing so that cannot be the cause.
 
Appreciate any feedback as I am reluctant to start restocking...
 
Thanks.

 

[FungusTrooper]

You don't have your own water testing kit?
 
How big's the tank, what filtration do you have, what oxygen, etc, etc. Gonna need a lot more info for this one. Any pictures, too?

 

[Noahsfish]

He said 20 gallons.  I don't see why there would be 16 dead fish just from going away for 2 days..  Did someone massively overfeed them?  Any visible signs on dead fish?  You don't need a fish feeder for 2 days, it could've overfed.  Fish can easily go for a week without food.

 

[DerpPH]

He said 20 gallons.  I don't see why there would be 16 dead fish just from going away for 2 days..  Did someone massively overfeed them?  Any visible signs on dead fish?  You don't need a fish feeder for 2 days, it could've overfed.  Fish can easily go for a week without food.

 
 
true. They can survive a LONG time without food. maybe you just put too much food on the fish feeder.  sorry for your loss.

 

[bigcheed]

i put one of those things in my tank once to feed my snails. it drastically change the ph in my tank and raised nitrate like you wouldn't believe. luckily my only inhabitants at the time where my two apple snails whom dident mind that much. shudder to think if id had it stocked with fish what the outcome would have been. took me a week to get the water back to normal. never again.

 

[fluttermoth]

It will have been the feeder block breaking down and polluting the water that killed your fish

Do a few extra water changes and you should be safe to add new fish. I really would recommend you buy a set of test kits for yourself, rather than relying on the shop to do it for you, and do restock carefully; a 20g tank is really quite small.

 

[Wills]

It will have been the feeder block breaking down and polluting the water that killed your fish

Do a few extra water changes and you should be safe to add new fish. I really would recommend you buy a set of test kits for yourself, rather than relying on the shop to do it for you, and do restock carefully; a 20g tank is really quite small.

 
Totally agree - the feeding blocks are a nightmare and not worth the hassle in anyway what so ever.
 
It also sounds like you had a lot of fish in a 20g - 21 fish in a 20g tank, and most of the fish make well over 2 inches...
 
I hate to say it as well but I would stop trusting your shop
 
As for treating the fish now - make sure you keep up with the water changes and if you see any white patches on the other fish you need to treat the tank - I would reccomend the Waterlife products I used them in my tank when ever issues arise and they have solved some massive outbreaks for me in the past. They also dont affect the filter in anyway so are advantageous over other meds IMO.
 
Wills

 

[DerpPH]

Well your tank was overstocked to start with and by adding more food that they can chew you only increased the nitrate and ammonia levels. Take this as a lesson and never overfeed. Oh and I recommend using API stresscoat when doing water changes. It reduces your fish's stress levels.

 

[attibones]

Actually, stress coat helps to replenish the fish's stress coat which helps it prevent infections, heal faster, etc. The stress coat is a layer of protective slime which covers the fish's body. You can feel it if you touch your fish, but handling the fish too frequently can actually cause loss of this protective layer.

Your mistake with this tank, OP, was that you had too many fish in a small tank and you added a feeder block. They really are terrible for your fish. The food quality is very low. They muck up your water nearly immediately. They can clog up filters. They bloat your fish. They also cause tremendous ammonia spikes (which your LFS can not test for due to the chemical exposure required in a liquid kit) which sends you through a mini-cycle. Speaking of cycling, how did you cycle your tank? "By the book" could mean you did your research or listened to your LFS or followed the instruction packet in your tank, assuming it was a "kit."

 

[PrairieSunflower]

Just a question... what sort of feeding block was used?  I've used feeder blocks twice now and they don't break down much at all except with the fish pick at it.... I forget the name of the brand I buy.