Weird Death

[muffinman3560]

I had a F8 and rudy scat...... I change the filters on it and moved the heater (set on about 72-75 because(and forgot to change it) with my last filter that kept the water at 80 it is a 250Watt heater for 30g tank) then in the morning they were dead and a crayfish... i had in the 3 corys, crayfish, ghost shrimp, F8, scat.When i got up the water was cold maybe about 72-75, do you think that it got to cold to fast? What do you think happened?

[sevenyearnight]

First, answer the questions in red.
You have fresh and brackish water fish together in a tank too small for all of them, even if they had compatible water types.
It's hard to read your post, but if you did something with your heater and the temp went from 80 to 72 in a few hours, as I think that's what you are trying to say, that could kill them.
But I suspect that it could also be that the water parameters were off too.

[chuckfriedrice]

was the heater removed from the tank ? Maybe a possible electrocution of the tank in habitants. But like seventy said you might wanna post your water params so everyone can help you better. .

[Pufferpunk]

IMO, that drop isn't enough to cause death right away. More likely contribute to stress which would lower their immune system, then they'd get sick & then die.

[xrayjeeper83]

Ya that far of a drop isnt a big deal. I unplugged Huey's tank for a few days and it dropped down to about 70 before I noticed. He is fine

[muffinman3560]

I was not keeping the FW fish in there I was going to take them out and put in my other tank but I have not had that much time on my hands to do it. I just got them Saturday, and changed filter sunday, then Monday morning they died.

I did a water change Friday, but I do not know if that would be important.

[RTR]

+1 to PP's comments.

Any known water parameters?

Could you clarify this: "....I change the filters on it ..." by providngh more detail>

[Iliveinazoo]

It's difficult to understand your posts but I think i've got the jist - If you changed out your old filter for new without transfering the media from the old one then you have lost your beneficial bacteria, hence creating a new cycle and with the amount of, and type of fish that you own then ammonia would build up pretty quickly and kill your fish

[muffinman3560]

+1 to PP's comments.

Any known water parameters?

Could you clarify this: "....I change the filters on it ..." by providngh more detail>

I changed from a power to conister filter. The flow rate is lower on the conister filter than the power filter.

I wish I checked the water parameters but I was not even thinking about it.

Sorry i am not that good at typing my thoughts

[RTR]

Did you transfer the used media to the new filter? If not, then what Iliveinazoo wrote is correct. You had an uncycled highly overstocked tank which killed the fish.

Canisters do not require the same flow as HOBs, they are more efficient than HOBs so need less flow for the same effect.

[muffinman3560]

i had the canister filter running on my other tank that had all guppies fry in it. i cleaned the filter but i did not clean the media.

[Pufferpunk]

Without knowing the parameters of your tank, it is difficult to say but when you have an entire wipe-out like that in a severely overstocked tank, its often due to ammonia poisoning. Any symptoms before they died.

[muffinman3560]

Without knowing the parameters of your tank, it is difficult to say but when you have an entire wipe-out like that in a severely overstocked tank, its often due to ammonia poisoning. Any symptoms before they died.

No they were fine, when i turn off the light and went to bed.

[Salmon]

Also to comment on PP's remarks, it wasn't an entire wipeout. Only the F8, scat, and crayfish died. He moved a cycled filter from one tank to the other, so there should have not been any cycling issues. The guppy fry tank probably had more ammonia being produced than his 30g imo, that may have caused it to become uncycled, but most likely it did not. I was told nitrites were at .5 ppm and that may have had a slight effect towards the fish dying, but seeing as how thats not terribly high I don't see how that would have killed them, even though it is supposed to be at 0ppm.

[eieio]

I was told nitrites were at .5 ppm and that may have had a slight effect towards the fish dying, but seeing as how thats not terribly high I don't see how that would have killed them, even though it is supposed to be at 0ppm.

nitrites @ .5 ppm is huge
what was the NH3 and NO3 at that point?
given that, and the lack of other parameters, how can we not assume that the tank was overstocked and polluted?