What am I doing incorrectly????

[Mandy]

I've posted on this site with a few questions before and you were all very helpful so here goes again...
I got a new 26 gallon tank in the beginning/middle of summer. I cycled the tank, learned I can't keep real plants alive , and have lost several fish now. I check my water regularly (3 x's a week in the beginning and now once a week) with all parameters being good. Ammonia has been zero, Nitrites zero and nitrates registering very very low on the index card I check it against (maybe between the first two color options like a 5ish). I started with 3 cherry barbs who relentlessy chased at one another. I added 3 more cherry barbs hoping they would settle down in a bigger group. Parameters all remained very good - no ammonia or nitrite and nitrate stayed low. I eventually lost 3 of the cherry barbs within 2 weeks. No diseases that I could see. I added 4 albino corydoras (all who are still doing well - phew) and then after I waited 2 weeks I added 3 more cherry barbs. Again, the barbs chased/attacked one another relentlessly and I lost 3 more. Next, I tried adding 4 rummynose tetras. They pratically didn't make it home from the store. One was stuck to the back and and three were belly-up before the next morning. I chalked that up to a bad batch from a new little pet store I tried. I waited and waited with my 4 corydoras and the 3 barbs I had left for a while. Then I tried adding a blue dwarf gourami. He was awesome. Very active and pretty to watch. Within the same week I also adopted a black molly from someone who was breaking down their tank. I watched them all closely and aside from the molly being very shy and hanging in the back by the bubble wall all the time, things seemed ok. Parameters remained great - no spikes ect. After about 3 weeks I added 5 little zebra danios. I've heard they're very hardy and I was really wanting something that wouldn't die since the tank seemed ok. Well, that was about a week and a half ago that I added the danios and now the newest victim to my tank is the dg. The dg lasted about a month give or take and then I came home yesterday and noticed his belly extremely swollen out of nowhere. Sadly, he died last night. I'm at such a loss - I don't know what I could be doing wrong. Between not being able to keep the barbs alive, losing the batch of tetras, the dg dying out of nowhere - it's getting really overwhelming. I feel terrible because as much as I check my water and do weekly 30% water changes, there is obviously something I'm doing wrong. At first I thought I was just getting bum fish from the pet store, but now I'm thinking I'm overlooking something. I waited 2 weeks before adding new fish with every new introduction (except the black molly) and I've never had a mini cycle as of yet, so no spikes. Currently, I have the 4 albino corydoras, the adopted black molly, 3 cherry barbs (all small and they look like males), and the 5 newer zebra danios. Is there something obvious I'm overlooking here? Any ideas as to why my cherry barbs kept dying off or the dwarf gourami? I still think the tetras were a weak batch, but who knows. Is my tank fully stocked at this point or should I still try to work on the barbs so they can have a school of 5? I'm at a loss...

 

[Hoontar]

I'm not an expert on the fish you have been buying, and under the assumption that your tank is sufficiently cycled and your water is in fact okay:

1) How's the temperature?
2) You're using tap water conditioner before water changes right?
3) Perhaps try a smaller weekly change, as to not shock the fish so much, try 10-15%
4) Some fish don't get along and stress one another to the point of death, make sure your fish are compatible in a community tank, and look into how to acclimatize them properly when you bring them home from the store
5) Sounds like your tank is approaching its capacity in terms of inches of fish per gallon. If your fish are dying then you shouldn't be replacing them right away, but rather wait to see if your remaining fish are affected, that might rule out certain problems.
6) Sometimes the fish we buy from the local store, especially the small cheap ones, are crap fish...

Hopefully that helps a bit...

 

[sheamurai]

Swollen belly MAY indicate internal parasites - maybe do a bit of reading on that and see if it applies?
As far as the barbs - if I have something die on me twice, I give up on it. There always seems to be a species of fish that just won't take to your tank/water/whatever/whoknows.
If the barbs you still have are not fighting - I'd leave them be. I have some "schools" that don't match book numbers but that doesn't mean they can't still be healthy and happy.
There are a couple of sites out there that can help you with the numbers game for how many fish you can stock in your tank.
AqAdvisor.com, and MOA fish sheet (google it, I can't find the link at the moment) will both give you an idea how your stocking suits your tank.
good luck...

 

[Badfish]

I couldn't agree with hoontar more. And a lot of large chains whom i won't mention ,petsmart lol, are good for supplies but the smaller local shops seem to be more knowlagble and their fish, to me, are generally more healthy. Maybe its because the big chains are just out to make a dollar where a "mom and pop" operation prob openened that store to make a living at what they love to do.

 

[JRB__]

As far as the barbs - if I have something die on me twice, I give up on it. There always seems to be a species of fish that just won't take to your tank/water/whatever/whoknows.
If the barbs you still have are not fighting - I'd leave them be. I have some "schools" that don't match book numbers but that doesn't mean they can't still be healthy and happy....

Very true, I totally agree.
Some small fish like barbs can be quite agressive fish, it may even just be one of your existing barbs who's dominant and is bullying to death the other barbs and any new ones you add.
As for your dwarfe blue gourami, thats sad because they are very pretty little fish. It was hopefully a one off caused by a disease he very well could of had when you bought him.
Also if your tank is at or is close to its fish capacity be aware that like their bigger brothers (normal gourami's) they are very territorial and will fiercely swim sideways with all their fins fully extended showing off their color to all other fish if they don't have enough room to establish a small part of the tank as their own. This aggressive displaying usually stays that way, rarely turning physical unless it is another dwarfe gourami. But all the same it is un-needed stress in your tank. Good luck!