unknown deaths

came home from work yesterday and found almost half of my livestock dead

members in my tank as follows
2 indo tiger, 2-2.5 inch
5 clown loach
1 silver dollar
4 dwarf gourami
2 unknown angelfish
2 SAE

dead fishes as follows
2 SAE
1 dwarf gourami
3 clown loach
1 dwarf gourami (both eye blinded) *died this morning*

it shouldnt be water problem as i've just 30% WC last sat morning as usual..
and the other fishes are fine and eating like pigs

any bro have an idea of what bacteria or disease that might be the cause ?

their diet is FBW

housing in 1.5 feet tank with hang on filter

Small tank, insufficient filtration & too much fishes.

Multiple choice. My guess.

bro, your tank is quite overstocked. Check ur remaining fishes for ich and please mention the filtration you are using now.

[pome422]

did you wash/change the media in your hang-on filter regularly? some hang-on filters use activated carbon, which can lose their absorbtion powers and leech out the pollutants (ie the nitrates and other nonsense) that they've absorbed, which can send water conditions going all over.

if you dun understand how each component of the filter media works, this can happen. once, my 15L tank (now gone) was fine, then suddenly water became very smelly and fishes started dying (and the tank wasn't overstocked). was using a hang-on filter with a activated carbon mesh (a-life brand if i remember correctly).

overstocked ah ? i still thought of getting more lovely clowns this weekend..hai..

now i think i will take out the gourami and silver dollar bah..and see how it goes..
thanks bros

anw..my hang on filter is ocean free brand..normally i will only change the wool..will not touch the medias..however, now that i recall, last night when i change water, the smell of the water was horrible..i thought it is because of the rotting bodies of the dead fishes

Too many fishes in a 1.5ft (bioload too high).

Therefore the HOF cannot handle the bioload produced by the fishes.

Only those hardy fishes will survive.

Solution: Either u reduce the fishes inside or upgrade your tank and filter system.

[stoner]

Multiple/Possible reasons...

~ Overstock

~ Insufficient Oxygen

~ Ammonia Poisoning

[ESP]

IMO, AC does not absorb NO3.

Originally Posted by pome422

did you wash/change the media in your hang-on filter regularly? some hang-on filters use activated carbon, which can lose their absorbtion powers and leech out the pollutants (ie the nitrates and other nonsense) that they've absorbed, which can send water conditions going all over.

if you dun understand how each component of the filter media works, this can happen. once, my 15L tank (now gone) was fine, then suddenly water became very smelly and fishes started dying (and the tank wasn't overstocked). was using a hang-on filter with a activated carbon mesh (a-life brand if i remember correctly).

Sorry to hear of your loss bro, but overstocking and over-feeding is a sure recipe for ammonia buildup. And ammonia, as you know, is toxic. So yours is a very likely case of ammonia poisoning. Only poisoning from either ammonia or nitrite can wipe off livestock overnight. Diseases will take a much longer time.

I suggest you do a massive water change, reduce your livestock and cut down on feeding. Better still, start implementing biological filtration in addition to mechanical filtration. The bacteria in a biological filter will get rid of ammonia and nitrite for you. For faster results (because bacteria takes a long time to grow to a sufficient number), try dosing bacteria manually with products like Prodibio's Biodigest.

Hope this helps.

[aquafanatic]

Insufficient oxygen. That's what happened to my fishes previously. After putting airstone, managed to save some of them.
Yet again, it can be many reasons.