Unexplained Deaths

[P14LCG]

Hi All, this is my first post and I'm afraid I do not know all the lingo.
I've recently been having a bad time with a new set up. My husband and i have an interpet AQ3 65 litre tank. We cycled it for 2 weeks and got the nitrate/nitrite levels under control before we started adding fish. Everything seemed ok. We added a few at a time, starting with a couple of male guppies, another couple of weeks later we added 3 glass catfish, another week or so later we added a pair of dwarf guarmi's. This is when it all started going wrong. Within days the female dwarf guarmi had died - she didn't appear to have anything wrong with her and we went back to the shop and replaced her with another. This new female seemed much more lively and after 3 weeks or so she started getting quite fat and her lower fin started sticking out a lot - we were really excited and thought that maybe she was going to spawn. However she died after 3 or 4 days. The male followed shortly afterwards and then 2 honey guarmi's followed with the same symptoms. We then had a shaul of neon tetra that were fine and suddenly started dieing, 1 or 2 a day. We went to our local aquarium shop and he said maybe we had an infection and gave us some tonic to sort this out. After a week or so and all the dieing had stopped we restocked choosing 5 cardinal tetra (they looked a bit bigger, more sturdy!) At this point our tank is about 3 months old, nitrate/nitrite wise is very stable. We do a 30% water change once every 2 weeks and clean the filter (not the substrate) at the same time. We always declorinate the new water. When ever we do the water change we always add the start up bacteria. I can't be specific about the brands or amounts being added as my husband takes care of it but he reads the instructions and I'm sure he's following them properly. Anyway in the last couple of days one of the new cardinal tetra had a brown spot on its back. We treated the water with an anti-fungal treatment and kept an eye on it but the other fish were bashing into him and eventually killed him, the next day another cardinal tetra died in the same way and then last night all 3 glass catfish (that we never had any problems with) died.
I don't know what to do. Are we keeping the tank properly? Is there anything else we should do or something we should stop doing? We've been asking in the local aquatic shop but things aren't getting any better. i do not want to replace any of these fish just incase.
At present we have:
6 male guppies (all healthy of various sizes)
1 Ansistorus (1 inch long max - seems fine)
2 golden sucking loach (1.5 inches long max - seems fine)
3 or 4 tetra (neon and cardinal) - They look ok at the moment, no spots and they seem bright.
3 small gold fish (2 x 1 inch and 1 x 2.5 inches, they were transplanted from a previous tank at the time of adding the first guppies - they are fine, never had any problems with them - seem to like the warm water)
Please help me - I'm getting very disheartened!

 

[bra_van_drakh]

umh...how big's ur tank ??? and is it planted ??? i do keep 10 cardinals in a 20gal wide, and doing very fine[see the topic "my current tank. ..is it stocked or over ???" for the picture]
does any of ur fish try to chase one another ??? how's ur pH ??? [very important]^^

 

[newfound77951]

What are your nitrate/nitrite/ammonia/pH/temp levels? When you say you have the nitrate and nitrite "under control", what do you mean? Nitrite should be 0 at all times in a tank with fish in it.

Your water change schedule sounds fine. What kind of filter do you have? When you clean it, do you replace everything that is in it? If you're replacing everything every 2 weeks then your tank is going through a mini-cycle every time and that could explain the fish deaths. Cleaning the filter should just involve replacing carbon (if you use any) and rinsing out (with tank water or tank-temp, dechlorinated tap water) any foam blocks or filter floss. Then the foam or floss goes back in. The beneficial bacteria that become established in your tank when you cycle colonize that foam, and removing it every two weeks causes the cycle to start again. You do not need to add the start-up bacteria, it is likely doing nothing as the beneficial bacteria live on surfaces, not in the water, and take a while to become established. I would stop replacing the filter media, keep doing the water changes and see if that helps (and check your water parameters).

Many of the medications sold by pet stores do more harm than good. If your water parameters are sorted out and you still get a sick fish, I would check here before buying and adding more chemicals. Also, the goldfish really should be in another, larger tank, they are stressing the capacity of your filtration (they are very messy fish).

 

[bra_van_drakh]

owwhhh...my bad, didn't see the tank capacity, that should be 17 gal, and i think the ither problem is that u're over stocked... . and i wouldn't agree more with newfound about those medications, i'd rather play with the temps and add a bit amount of tank salt .. .

 

[P14LCG]

I think one of the problems was the gold fish. We caught one eating a guppy yesterday so we have removed them and given them away. I think that explained the majority of the tetra disappearances.
Our hardness and PH are slightly high but we have been advised that that is normal for our area and it would stress the fish more if we were to try and lower these. Nitrite is 0 and Nitrate is low, ammonia is also very low.
When we clean the filter it's just rinsing in declorinated water - we just cleaning up a bit not changing anything.
I was slightly over stating the water changes though. We have been topping up more often that proper partial water changes which now we realise doesn't count and is not good. We have been advised that 25-30% every 2 weeks is good.
We have got some aquarium salt to add next time. We are down to just 5 male guppies and 3 neons, 2 golden soaking loach and 1 ancistorous.
What is the rule of thumb for the number of fish allowed. We were told that you could have 1 inch of fish for every litre of water (not including the tail) is this correct?

 

[bra_van_drakh]

it's not usual though for a gold fish to nip upon other fish .. .

arent yuo wrong about that 1" per litre ??? i think it should be 1" per gallon, an even that i still think it would be too crowded. ..i put 10 0.8" cardinals inside a 20 gal, and it already seemed a bit crowded[ammonia 0 nitrite 0 nitrate 8]. . .the amount of fish inside a tank should depends on ur cycle i guess, if the bacteria cant mannage to cycle it[ammonia must be 0, nitrite 0, nitrate <10], then dont add anymore, and further more, if ur nitrate's higher than 10, then it's crowded indeed. . .

 

[newfound77951]

We were told that you could have 1 inch of fish for every litre of water (not including the tail) is this correct?

No it isn't. The usual rule of thumb is 1" (of adult fish size) per gallon. It is not a hard and fast rule, though, just a guideline. Obviously 4 1" tetras will take up less space than 1 4" fish.

 

[bra_van_drakh]

then i sam keep a school of mostly 20 cardinals then ??? i thought now it's already too crowded

 

[P14LCG]

Obviously 4 1" tetras will take up less space than 1 4" fish.

Like you say, neon tetra take up hardly any room.
I think our plan, going forward, once we've had some time with no deaths etc (I think the gold fish was the main problem now as all the tests have come up ok) is to get a shaul of 10 neons and maybe 3 hatchet fish. Obviously added in stages. Then we will be complete!