Why did my guppy die?

[janele]

I have been running a 40l tank for 6 weeks now, and nitrite and ammonia readings are 0. I have 3 platies, 5 neon tetras, a dwarf gourami, 2 small crabs and 3 male guppies. I had a fourth guppy that died within 12 hours of getting him, and I've had 2 of the other guppies for 3 days. The one that died was the first fish that I introduced 4 weeks ago. Any clues? Are the others likely to die too over time? I had 0.25 nitrite reading a week ago but this has been 0 for 5 days now. Please give me some ideas as I'm about to give up on this depressing hobby! Each morning I dread looking at the tank in case any more have died...

Also, guppy didn't show any signs of sickness (not obvious to the untrained eye anyway!).

 

[snowyangel]

Sorry to hear your loss. I had guppies dying quickly and i found it was the nitrite problem i had. I've been doing more water changes and feeding less and i haven't lost a guppy yet(ive had one for almost 5 months now). But i know u said the nitrite is fine. When they die are there gills red? How often do u clean your tank? Guppies are sensitive to pH also...

 

[janele]

Thanks for your reply Laura. The gills don't appear to be red. The previous guppy that died looked like his tail had disintegrated, but this one looked fine.

I have been doing a 15% water change every 3 days as we were concerned about the nitrite level at one stage. The pH is high - 8.2 - but I've been reading it is more dangerous to change it than leave it. I asked at the fish shop and they said they used the same water source with the same pH so we should be fine, but it seems very high. Maybe we just can't keep guppies with that pH??

 

[Lithril]

Bogwood can help lower the pH, you could also try using RO water from ur lfs for water changes (just be sure to add the right minerals back in with something like electo-right).

You may also want to try adding a small airpump with an airstone to the tank. What temp is it set at.

 

[janele]

Temp is 24C. Do you think 8.2 pH is the problem? And could it take 3 weeks to kill a fish? This morning I found we had lost a platy too.

 

[Lithril]

If the nitrites have been high for a while it can affect the fish long term (another reason why cycling with fish is a bad idea), keep an eye on water parameters for a while to make sure they're not spiking but you may be suffering the aftermath of a large spike from when you set the tank up.

 

[janele]

One last thought...could my small crabs be attacking the fish? They are about 3-4cm wide. Apart from the last guppy that I lost, all the fish have died at night. (3 neon tetras, 2 guppies, 1 platy, 1 danio).

 

[aquarius]

that's a possibilty. what kind of crabs do you have?

 

[janele]

They are red claw crabs. I feed them blood worm twice a week. If this could be the cause, I have only seen obvious signs of 'attack' once, on the danio. WOuld it be more evident if this was the cause of the fish deaths?

 

[aquarius]

well this what i found on them

<<The Red Claw Crab usually does well with community fish, though it has been known to chase those who venture too close. On occasion, they have been known to catch and eat very small fish.>>

so i guess it's possible that the crab attacked the guppies since they're pretty small

 

[janele]

Looks like the crabs are the culprits for at least one of the deaths - we found the missing platy from last night half eaten in their 'cave'.