- Pet forum for dogs cats and humans 


Question re: Fish Death

November 9th, 2006, 01:11 PM
I recently experienced some odd goings on in my 30gal tank. It's not even close to capacity in fish, the water has been tested repeatedly by myself as well as the place I get my fish (small local store), and yet, every 4 weeks or so, one of my seemingly healthy fish disappears, and I find it dead (either buried in the gravel or hanging one of the live plants). I've maracyn'd the tank out of fear it was something biological, since the fish that have perished have either been fairly young or had been in the tank awhile. Any thoughts on how to keep the remainder alive?

November 9th, 2006, 07:50 PM
Hey there,
couple questions:

How long has the tank been set up?
What fish are in it?
Readings for Ammmonia:

What fish have died?
Have you added any fish lately?
How often do you change water and how much?
How often do you clean the filter?
Do you clean the filter at the same time as cleaning the tank?
Do you gravel vaccuum?

Have you added anything to the tank recently - meds,
salt, chemicals, ph adjusters, etc:

This info should help uncover whats going on!

pug lover
November 9th, 2006, 08:21 PM
could be something as simple as overfeeding as well

November 10th, 2006, 08:38 AM
- Ammonia readings are less than .25ppm - negligible on all accounts
- Nitrates/Nitrites are the same, all is in good standing
- I do water tests weekly with a 25% water change monthly (bucket sits for 48 hours before adding to the tank, with full testing, and I only use prime - my tap water is really really good)
- I have a biowheel and standard charcoal bag, the biowheel has never changed, the filter bag gets changed every 3 months and NEVER at the same time as the water change.
- I've vacuumed the gravel 4 times in the last 10 months, so essentially every 2 months, and again, never at the same time as any other large changes like the filter bag.
- The tank has been running for 14 months now, I only put fish in it 10 months ago as I did a 4 month fishless cycle on it, and stocked 3 zebra dainios at month 4, then let it sit for 2 months, then added 2 flame gouramis, let it sit for another 2 months, then added an algae eater, then another 2 flame gouramis 2 months ago. In that time, the algae eater disappeared - I mean literally, I did a full cleaning on the tank and could not find his remains (this was after not seeing him for 2 days which was ODD). 2 of the 3 dainios also died - one I found dead in the evening (she'd been alive that morning), and the 2nd disappeared shortly thereafter (again, pulled the tank apart and could not find the remains) One of the new gouramis perished for no reason, had been in the tank for a month with no visible issues (including interspecies aggression - they all schooled together). puglover, I'm really careful about feeding since I'd lost tiger barbs in highschool to that - but great suggestion and one most welcome :) Everyone else is behaving normally, they all school together, and I'm baffled but will be adding nothing else until I'm sure the tank is 100% ok. Any thoughts/hints/suggestions are welcome, my fish mentor is also stumped since his tank only has death at extreme old age, not for random odd things like mine :/

November 10th, 2006, 04:18 PM
Hi there,
my concern is that you say you have ammonia and nitrites and
nitrates are neglible.
In a cycled tank, you should always read 0 for ammonia,
0 for nitrItes, and nitrates always over 5ppm - usually they
sit around 20-30ppm in most peoples tanks.

The ammonia could be caused by the fact that youre not
vaccuuming the gravel enough.

A Good water change schedule would be 35% water changed
weekly with 50% of the gravel vaccuumed at that time.

If youre not doing enough water changes, crud, poop,
and mulm can build up in the tank to a level that causes
ammonia spikes, and every time the ammonia spikes,
a fish dies.

Id increase your water changes to once weekly, at least 10%,
with 35-40% being much better. Always alternate sides when
gravel vaccuuming, one time do one side of the tank thoroughly,
the other time do the next side. This will prevent your beneficial
bacteria from being robbed from the tank.

The filter bag should be rinsed in used tank water once monthly,
I usually take a small container, scoop up some tank water,
and then scrub the bag around in it till its as clean as it will
get, and then pop it back in.
You have a bio-wheel, so cleaning the other media will not
damage your cycle.
The problem with carbon is, that it only sucks crud out of the water
for about 1 weeks time. After 2 weeks, it starts releasing the chemicals
its absorbed back into the water column. This is why you want
to rinse it in used tank water regularly.

I think if you improve your cleaning schedule, youll see your
ammonia drop off, and wont lose any more fish.