Newby, LFS gave bad advice, now have a tank of aggressive fish!!! Help!!

HI everyone, I'm new to fish keeping and this is my first post.
I recently got a 120 litre tank and went off to the LFS to buy my fish. Over the last month I've added a few new fish every week.
3 black skirt tetra
3 danios
2 red gouramis
1 blue gourami
1 betta
1 red finned shark
2 corydoras
So AFTER the LFS told me all the fish would get along fine I came home and did some research just to check I how to look after and feed them properly. I quickly learnt that this is a terrible mix of fish!
As it stands the betta nips at the tetras, the shark nips at the blue gourami and the blue gourami nips at the red gourami. It all seems to be just 'get out of my way' nipping more than dangerous but I'm terrified of coming home to a bloodbath!
Is there anyway this will ever work?
There is lots of live plants and a cave in tank and I'm going to buy more this weekend.
Thanks for any advice x

P.s I had no idea about cycling but did leave it empty for a week running. I have since learned and do regular water changes and my friend pops over and tests the water sometimes as I don't have kit.

 

There is a link here about cylcing you may want to read.
I have learned that most LFS people really don't have a clue about fish. This forum is SUPER AMAZING for info. I trust the people here...
You will like it here.

 

HI Bellaboo, you came to the right place! Unfortunately that group of fish will never work together. The most immediate first thing I'd do is return/re-home the Betta and one of the Gouramis... and then the red shark - he'll out grow that tank quick.

Hope this set back doesn't discourage you! Now that you're doing the research, it's going to be really fun

 

Hello and Welcome to Fish Lore!

I hope you enjoy the site!

Ken

 

I'm really gutted to be honest, I'm going to take them back to shop as its there fault. It shocks me that they will let you buy fish without me too ing cycling or how big there going to grow. Thanks for replies.
Anybody think its worth leaving them for a few weeks to see what happens?
I have a 20 litre set up and running in add I need to remove fish fast

 

Welcome!

 

Welcome To Fishlore!
The cory catfish should be in a larger school of at least 5.

 

HI and welcome! I have Dwarf Gourami (DG), Blackskirt tetras, and also corydoras (corys), but not in the same tank. I agree that these are shoaling fish and need at a minimum 5 of each. I have several Gouramis in a well planted 55gallon. A Betta can be very aggressive but usually not with other types of fish (someone correct me if I am wrong) and the shark, well they are pretty aggressive.
You might want to add plants if you plan on keeping the gouramis but I have no idea how big a 120 litre is but you at least need, in my opinion, plenty of space if you have more than one gourami!
Good luck and I hope that you are able to return any fish that do not fit your needs.

 

A 120 liter is about 30 gallons.

If I were you, I'd take back two of the gourami's, the betta, and the red tail shark. Then if you fill out your schools of tetras, danios, and cories to at least 6, you may still have room for some additional fish. (Of course don't add any more fish until your tank is cycled.

Nitrogen cycle <-

 

Sorry. Yeah I don't think there's is a point to waiting it out a few weeks. If anything, the pet store likely won't take them back after that long. Definitely take the betta out immediately so it doesn't get nipped at so much. I have black skirted tetras and they nip each other like crazy despite HanI g the right school size, tank space, water parameters etc...
I had to bring back a couple fish throughout the starting up of our tank because of misinformation ( black shark and a Chinese algae eater and dwarf neon gourami). It's such a pain. But so much nicer having a tank that is somewhat peaceful. ( those black skirts can be punks !)

Personally I'd keep the blue gourami ( they get to be a nice size) and add 3 more black skirts ( they are punks but fun to watch during feeding time) and return the rest. And return the rest
Not sure if the Cory's can stay in that tank after adjusting then to the right school size. I think they mainly are bottom dwellers, though.