Tank Problems For A Begginer...

[bethxxxox]

The tank has been set up for about 2 weeks now, i put fish in it from day 1, which i now know that i shouldnt, but its been done now... The 3 fish I put in from the start are all still ok,they were a guppy and 2 yellow spotty ones, these were all older fish that were in the last tank that I had. Since then I have added 3 more guppies, a plec, 2 red and black stripey fish, 8 neon tetras, 4 cherry barbs, 2 glowlights and 2 mollies. These were all added to early as i now know that I sould have waited for 3 weeks

My problem is that 2 of these fish have died and now another one is looking ill too. I feel really bad because I think this is probably because of something Ive done wrong and I was hoping someone might know what it was. The first one that died was a mollie 2 days ago, it died the same day that I brought it back from the petshop, the other mollie i bought is still ok. It was really lethargic from the moment it went into the tank and just sat at the bottom with its fins tucked in untill an hour or so later it died. I introduced the fish by putting the bag into the water for an hour before letting them out.
This morning i noticed one of the red and black striped fish doing a similar thing, hes still very active at the moment but his fins are tucked in and he has been hiding in the fish hide a lot, which is unusual for him. The next fish that died was a tetra he was swimming upside down before he died and was doing this before he was even out of the bag.

Sorry if this is really long but I wanted to give as much information as I could so someone might be able to tell me what I can do to stop anymore from dying.

 

[I'm the new guy]

What size tank is it?
If your fish are coming in to your tank lethargic, it may not be your fault. There is a good chance they are bad fish from your store.
It could be the fish went into shock. You can do several things to help minimize the chance of shock. Don't shake the bag. Acclimate your fish to their new tank slowly. Don't take any detours on the way home from the pet store. You want to get your fish home as soon as possible.
The molly could have ich. I would check all your fish for ich. Ich is a parasite that will kill your fish, it's very common especially in molly fish. If you see any tiny white spots on your fish that shouldn't be there they probably have ich. Ich is treatable. You should search fish with ich on the web, you will get all the info you need.

Check your fish for ich.

 

[fluttermoth]

It sounds like the typical set of things we see caused purely by ammonia poisoning in a 'uncycled' tank.

This basically means you don't have a colony of good bacteria living in your filter to eat the fish's wastes for you, so they're building up in the water and poisoning your fish.

You really need to get yourself some test kits, for ammonia and nitrite, so you can monitor the water quality, but until then change nearly all the water (leave just enough for the fish to swim upright before refilling) every day, making sure the new water is warmed and dechlorinated.

 

[lolobunnz]

It seems like a mix of uncycled tank issues with poorly petshop fish.

If you dont have an api liquid master test kit i would strongly urge you to get one.

Change some water out when u have ammonia with treated tap water. Sounds like ammonia issues to me. I would syphon the gravel and do a nice sized water change asap.

 

[reggie]

Yes, seems like a combination of an uncycled tank and sick fish from a bad petstore.  If water in your area is too alkaline, I would combine it with distilled water. Too high [alkaline or basic] a pH, turns ammonium ion into ammonia, wich is far more toxic. For the future: cycle first, and introduce stock later.