Tank Has Been Wiped Out Almost... :(

[kirkster]

Hello Guys,
My first post so hello from me.

I am desperate for some advice.

My 240 litre tank with Fluval 305 filter has been up and running for three months. I was slowly stocking it over that time and had about 40 fish in total. Everything was cool -all levels seemed OK.

I then cleaned the filter (have done this before). I thoroughly rinsed all the sponges and media in the old tank water that i was changing. THis got all the slime and everything off the sponges. Two days later I added six new ballon mollies - one of my favourites. DISASTER!!! Within eight days I have lost 6 neons, 6 guppies, 8 platys, 6 serpae tetras. In other words nearly all my new stock!!! Strangely most of my older stock I transferred over from my old tank are OK - as are my clown loach. I have been using cycle and aquarium supplements at the recommended doses

What have I done wrong??? Did the new mollies have some disease? Or did I wash away all the good bacteria in the filter (even though I cleaned in tank water)? Should i have just changed a swapped out two filter sponges and left the others as they were?

Really worried, would not want to wipe out fish like this again - poor things!!

Any help ro guidance appreciated.

Steve

 

[Jonty]

Did you quarantine the Mollies? I imagine they were carrying some kind of disease.

 

[River Dog]

Hello and welcome. The first mistake you made was in your words" I thoroughly rinsed all the sponges and media in the old tank water that i was changing" You should only clean half the media at a time. Using tank water is good, but cleaning everything is wrong, as you have washed away the good bacteria you have built up with cycling the tank. Did you cycle the tank before adding fish? If not adding more fsh probably tipped the balance of an already unstable tank. You say you are still using cycle and in your words " aquarium supplements at the recommended doses" what supplements are you using? Also a really good idea is to have a small quarantine tank always ready, that way when you buy new fish, you pop them in the quarantine tank for a couple of weeks, then you will see if the new fish have any health problems. Then you can deal with the problem, before you put them into your main tank. It is always disheartening when you loose fish, but hopefully the good folk on here will steer you in the right direction.

 

[fishyfeet]

with externals i only clean the sponges and the tub itself i never clean the ceramic media as this would wipe out too much bacteria, and then you placed even more stress on the bacteria that was there, it just wasnt enough and you had an ammonia spike i suspect. di

 

[mattlee]

have/did you test the water since cleaning the filter? even though you cleaned it in tank water if it was cleaned too much then you may have lost some of the bacteria causing a mini spike.... especially if new fish were added soon after.

the fish that died, did they have anything like spots, sores, fungus etc or any unusual behaviour like hiding, clamped fins, colour loss etc etc if not then mt guess it was a spike in the tank

 

[PJGoblin]

Hi Jonty

I did the same as you by putting new fish in a tank that was well established, until I introduced
some new tetras and got "white spot" and wiped out my tank....Nightmare, Totally Gutted ..

Learnt a valuable lesson .!

Now have a quarantine tank (12lt plenty, small pump and spare heater £25)
You can even treat the water to "serialise" before putting in main tank if you wish.
(depending on fish)

I never put anything in tank now to much trouble not Worth the hassel....

Old boy once to me I was to clean when I first started, I have "tetratec 1000" with 4 sponge filter.
I was the doing the very same thing as you (rising all in tank water.).

He told me "less is more" so I only clean 1 of the 4 per week and rotate the cleaning of them.
Allowing good "bacteria" in effect to do its job, buy cleaning all together stresses the tank bacteria by removing them....!

All in all still could of been you adding asick fish to the tank, hard to tell rule of thumb by have a secondary tank you are able to treat only that and not all the main tank stressing all the fish even if the are fine and not ill.

Hope this helps.

Regards

PJGoblin

 

[WILDER]

You are only meant to touch one sponge at a time.
You do the rest over the coming weeks.
You can lose to much beneifical bacteria cleaning them all at once.


How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.
What test kit are you using.
Any symtoms to go on.

 

[kirkster]

Hello guys, thanks for these valuable insights!!

I reckon the issue is the ammonia spike, as these posts seem to be alluding too. Oh dear, in my ignorance I wiped out my poor fish.... All levels are fine now though. Would an amoonia spike, that occurred a week ago have shocked the fish enough to have killed them several days later (when the levels ha recovered)?

When would you start to restock? I am thinking of leaving for a month to settle down now. Then i'll start like i did before, four or six fish per week.

I would like to use a quarantine tank but very difficult to justify this to the wife..... Could I use a small tank sht in the cupboard under the main tank? it'd be in the dark but that would not be a problem would it as long as the lights come on?

Steve

 

[philak]

This " only touch or clean one sponge at a time" stuff is news to me , i've never read it on this forum before . I've always been told only replace one piece of media at a time but gently rinsing all the pieces out at the same time in used tank water is fine. Vigourous cleaning of any sponge or ceramics is not needed.

I've followed that advice and never had a problem. In my experience if you only rinse one piece of media at a time you will end up with a filter full of cr*p just by trying to remove one piece.

I need advice how to remove the central sponges in a Tetratec 1200 without disturbing all the other bits in there if this is the case.

 

[WILDER]

I only touch one sponge at a time and that's what I was told to do.
I rinsed all the sponges once and the tank went into a mini cycle.

Sorry for your losses.
R.I.P.

An ammonia spike can soon kill fish off.