6 Fish Died In The Night

[misspiggy78]

Ok, heres the story. Last october my 9 year old son started his tropical fish hobby, unfortunately we had no idea about cycling etc, and just went under the instruction of the guys in pets at home, he started out with 5 neon tetra's which soon went down to 3. We went back to pats at home weekly to get his water tested and 8 weeks later his water was finally good (after having constant problems with ammonia and nitrites). So he added some mollies and just recently 2 guppies and 2 butterfly plecs (i think thats what they are-the guy said they dont grow big and are coldwater or tropical). Anyway the filter we have fluval 2+ had been playing us up and kept cutting out, and last friday, after it cutting out in the night and us waking up to find a dead plec and really cloudy water we decided to take it back.
Now i couldn't get a replacement of that model as they didn't have any left, so on saturday we ended up with the new model the fluval u2. Yet this morning we wake to find 6 fish have died-1 molly, 1 guppy and 4 tetra's. So my question is, could this be because the filter is new and hasn't had time to mature??

Anyway, i've done a 50% water change and cleaned the tank as it was slimy from the cloudy water.
Here was its stats before the change:
60l tank
Nitrite between 0-0.25 (was 0 two days ago)
Nitrate 0
Ammonia 0
Ph 7.6

and here's the fish that remain
2 balloon mollys 1 male, 1 female
2 female mollys
1 guppy
1 tetra
1 pleck
and 6 guppy fry.

Any ideas?

 

[minxfishy]

Did you use the filter media (sponges, ceramics - whatever is in a fluval 2+) from the old filter and place it in the new filter? If not, then you have no bacteria again and are back to cycling the tank with alot of fish in it as like the 1st time. If you have kept the old filter media and placed it in the U2 filter, then you should be ok and are experiencing a mini cycle for the added fish which you introduced.

Over the next few days (if you kept the media) test daily to ensure that you dont have a large ammonia or nitrIte spike and anytime the water gets above 0.25ppm for either, then do a w/c to get the levels down again.

If you didnt keep the media, then you are going to have to test daily and do as many changes as it takes daily to keep the ammonia an nitrIte levels to below 0.25ppm until the tank finishing cycling again, which is roughly 4 weeks.

 

[Underwurlde]

^ Yep, you ABSOLUTELY need to transfer over the old filter media into the new.

Stats seem fine... (even pre-50% water change). What kit are you using to test your water, using Pets@Home still?

You have a small tank, and these are not so forgiving of 'mistakes', but 6 dead overnight is very weird.

Andy

 

[misspiggy78]

Firstly thank you both for your replies. I'm using the api master test kit. The filter media had to go back with the filter, the only thing i have left over is the carbon filter and the other additional white one, but these don't fit in the new filter as its a combined cartridge.
I'll keep doing the water changes, i'm just gutted that this has happened and we are having to, in effect, start again.

 

[Underwurlde]

For future reference then: Even if filter media does not fit, there are always ways & means of transferring media.

Andy

 

[minxfishy]

Unfortunate you returned the media, in which case you will need to test daily, sometimes twice, three times even and do the water changes needed to keep the levels safe for the fish. You can do 50% w/c in a relatively close period of time and not hurt the fish, just remember to dechlor the water and temp match it as closely as possible.

 

[misspiggy78]

Unfortunate you returned the media, in which case you will need to test daily, sometimes twice, three times even and do the water changes needed to keep the levels safe for the fish. You can do 50% w/c in a relatively close period of time and not hurt the fish, just remember to dechlor the water and temp match it as closely as possible.

Thank you. The readings i have just done are :

ammonia 0.25-0.5 (can't really tell the difference between the colours)

nitrate 10

nitrite 0

Should i do another change now? or wait til tomorrow?

 

[Underwurlde]

An important part in testing Ammonia content in water is to also know the pH of the water.

'Ammonia' test kits actually test for the COMBINED level of Ammonia (nasty) AND Ammonium (safe).

The pH of the water (and to a lesser extent the temperature) then predicts the ratio of Ammonia to Ammonium. The important thing to know is the Ammonia levels.

I think your tank is now going to have to cycle / mini-cycle again, purely based on the presence of 'Ammonia' & no Nitrite.

I would also do another 50% min water change, Get that ammonia DOWN!

Andy

 

[misspiggy78]

Thanks Andy, whilst you were writing that, i actually did a 25% change and retested ammonia and it was at 0.25, so i'll check again in the morning and do a 50% change then. Is it best to do it really early, pets @ home said something about water being best before people start getting up for showers, so if my baby wakes me up at 6 again then i could do it then, if you think it would help?

 

[minxfishy]

Doesnt matter when you do it, just so long as you keep them below 0.25ppm, never heard of water being better in the morning!

 

[pippoodle]

have you got anyone living near you that could give you some mature media , have a look in the media swap section and see if anyone is near you to give you a bit of sponge or floss that you could trim and fit into the filter to give it a bit of a kick again

 

[Underwurlde]

Note 0.25ppm is not 'safe'. Safe levels is when this reading is ZERO (which incidentally doesn't mean 0 ammonia in the water BTW, just LOW levels).

Letal amounts of ammonia for fish is anything above 0.02ppm.

The test kit is showing 0.25ppm for BOTH Ammonia & Ammonium.

So, using your result of 0.25ppm: I'll assume your pH is 7 (neutral) and water temp of 25C.
This gives a ratio multiplier of 0.1126%, i.e. levels of nasty ammonia of 0.00028ppm. Factor 10 below Lethal level. Good..

BUT...

Let's now assume your tank wate has a pH of 8.0 and water temp of 27C. Taking the SAME 0.25ppm reading:
This gives a ratio multiplier of 1.1146%, i.e. levels of nasty ammonia of 0.0028ppm. OOPS, lethal!!!!


Don't assume.... do a 50% change as I've suggested!

Andy

 

[misspiggy78]

Note 0.25ppm is not 'safe'. Safe levels is when this reading is ZERO (which incidentally doesn't mean 0 ammonia in the water BTW, just LOW levels).

Letal amounts of ammonia for fish is anything above 0.02ppm.

The test kit is showing 0.25ppm for BOTH Ammonia & Ammonium.

So, using your result of 0.25ppm: I'll assume your pH is 7 (neutral) and water temp of 25C.
This gives a ratio multiplier of 0.1126%, i.e. levels of nasty ammonia of 0.00028ppm. Factor 10 below Lethal level. Good..

BUT...

Let's now assume your tank wate has a pH of 8.0 and water temp of 27C. Taking the SAME 0.25ppm reading:
This gives a ratio multiplier of 1.1146%, i.e. levels of nasty ammonia of 0.0028ppm. OOPS, lethal!!!!


Don't assume.... do a 50% change as I've suggested!

Andy

The water temp is 24 degrees and the ph is 7.6, i'd better go do another change. I'll have a look and see if anyone near me has any mature media, thanks for the tip.

 

[Underwurlde]

24C at pH of 7.6, that's 04374% x 0.25ppm = 0.0011ppm (actual) Ammonia, factror then of 18 below lethal levels. This is still isn't great though, so you are correct to do another water change perhaps. You will now be cycling with fish. Not great (for the fish) but can be done.

Alternatively, can someone look after the fish for you / LFS while you fishless cycle?

GL

Andy

PS, actually measuring pH, is VERY, VERY, VERY difficult. The result you've got there will be an indicator ONLY. Also not that pH is base10 logarithmic. (pH 8 is TEN times more alkaline than pH 7 etc etc).

 

[misspiggy78]

Right, did a 50% water change yesterday and today, but also removed the carbon/polyster combined cartridge from the filter in order to add some meds as i noticed a white spot on 1 of the fish. I have added a piece of polyester (the one that removes discolouration) that i did keep from the old filter and i retested after the water change this morning and the results are

PH - 7.6
Ammonia - 0
Nitrite - 0
Nitrate - 10.

Thats ok isn't it? it appears that my stats have gone back to what they were. I'll keep testing and monitoring.