Lucy_kk

Yesterday i bought a heater for my 10 gallon tank with 5 minnows (they have been in there for about 2 years) in to make it into a tropical tank. I then bought 2 harlequins, 2 neon tetras and 2 small silver flat fish whose name i dont know. I was away last night and have returned this morning to find both the harlequins stuck dead to the filter, a dead tetra in the plants and i removed a dead silver one from the surface late last night. I did a 30% water change and did a nitrate test and it came back very positive so i did another 30% water test and it has still come back with a little ammonia present. Should i do and larger water change?
I have lonely v tiny tetra left and a silver small flat fish, and all my minnows are breathing near the surface and are very lethargic and tbh look nearly dead!
What should i do? I have loner schooling fish now and i am worried for the minnows.
I have the tank at 22 degrees celcius, which i have been led to believe is okay?

PLease help me!
Many thanks, Lucy x

Boxermom

Yes, you should do a large water change. You added too much stock too quickly and kicked up a mini cycle and they are suffering from ammonia and/or nitrite poisoning. When adding fish, you should only add a couple at a time to allow enough bacteria to build up to handle the extra load. And you should definitely find out what kind of fish the silver one is. Hopefully you didn't end up getting something that'll grow too big for your tank.

You have incompatible fish, though. Minnows actually prefer cooler temps, not higher tropical temps. 22c should be okay for them but I wouldn't go any higher. Meanwhile, neons and rasboras prefer it higher, around 25c.

Isabella

Like Boxermom said, you have added too many fish in a short period of time. When you do that, ammonia and or/nitrite can suddenly rise to toxic levels and kill your fish, or make them very sick. This is because there are not enough of the beneficial bacteria to deal with so many fish wastes after you add a lot of new fish to a tank. The bacteria develop slowly, therefore you need to stock your tank very gradually. When you want to add more fish, always do it gradually, adding 1 (or 2 at most) fish at a time, say once a week. However, when your tank is already fully stocked, you shouldn't be adding any fish at all. When a tank is fully stocked and you add more and more fish to it, you can get ammonia and/or nitrite poisoning as well.

Your fish are most likely dying from ammonia and/or nitrite poisoning. If you have the test kits for all three, can you please list your ammonia, nitrite, and nitrate readings? The best you can do now is perform large and frequent water changes in order to continuously remove the rising ammonia and nitrite from the water.

Lucy_kk

My nitrite and ammonia measurer's do not give me a numerical reading they just turn a clour which i have to compare to a chart. Thanks for advice, my tank is back to healthy levels now. All in all i lost 3 of my original minnows including my rly old gold one ; 2 harlequins; 1 unidentifiable silver fish. I went bk to my LFS today and they have given me two danios to start building my tank up again so hopefully this time i will be more sucessfull.
Many thanks for help.
Lucy

Boxermom

Sounds like you are using test strips. We highly recommend getting liquid test kits, as the strips are very inaccurate. This is the one we usually recommend: http://www.drsfostersmith.com/Produc...&N=2004+113074 Its vital to have a good, accurate test kit.

Lucy_kk

Thanks for the advice, after using the danios i also added a new treatment to my tank which contains live bacteria which sets the nitrite level leaving me able to add as many fish as i desire at any one time wthout upsetting the nitrite levels. I was at first sceptical as to whether this would work but i have tried it now twice and i have more than doubled the stock of my tank in just over a week!! This stuff is amazing and not even that expensive! I now use it every time i do water changes and my nitrite levels have been perfect ever since.
I also identified the miscellanious fish in my tank, they were neon blue dwarf rainbow fish.
Now my stock is:

Phantom tetra x4
Neon tetra x 4
White cloud minnows x 2
Neon blue dwarf rainbow fish x 2
Zebra danio x 3
Leopard danio x 1

Thanks everyone for all your advice!

Butterfly

all these fish are in a 10G right? Thats way too any fish in a 10G(approx. 21 adult inches of fish). Sorry. If you choose to keep all of them I would advise 2x a week water changes and a very close watch on your water parameters (Ammonia, NitrIte and NitrAte)
Carol

Lucy_kk

I know dw! I intend to get another 2 tanks in the foreseeable future (bring on payday!) so when i do i will spead out my fish into one of the tanks. I also really want to get a betta but have never had one before, i have read that they can be kept in small 5G tanks 'betta tanks' but i am not sure. Isnt this a little cruel? I am aware that males have to be kept by themselves etc but i am not sure about whether they can be kept with other smaller species like my tetras? I also really want some dwarf gouramis but i mean all in good time!

8)

Butterfly

dw? Bettas can be kept in 5G tanks with a couple of ottos OR a couple of corys. Just about anything else that swims at his(Betta) level will be looked upon as an invader and dispatched quickly. If not they will nip his pretty little fins to pieces.
Please concentrate on getting the fish you have taken care of first How are they doing by the way?
Carol

Lucy_kk

Ok thanks for betta info. I need to do some more research before i go and bring one home first though anyways!!
All my tetras and stuff are doing great and i chk the water parameters everyday and they are perfect. The tank seems to run smoothly on a 10% change once every 10 (ish) days.

p.s: (Dw= don't worry)

chickadee

Bettas are members of the Gourami family and so if the day comes when you decide to get the Gouramis and the betta please do not consider putting them together as the Gouramis will brutalize the Betta.* There have been a couple of Bettas killed recently by the mixture of the two.

It is a pleasure to meet you. I do not think I have posted to you as yet. Welcome to Fishlore.com. We have a great group here and all love our little fish. I hope you enjoy being here with us as much as I have enjoyed being on this site.

Rose

hopesmom

lol I'm so glad you explained what dw means! I'm new to this computer lingo, and I couldn't for the life of me figure dw out! I thought (ha ha ha ha) maybe it meant dim wit ...but the conversation wasn't ugly, so...I didn't know!! ha ha ha... this is so fun!

Lucy_kk

Lol no worries, and also dw chickadee i was thinking about some ottos in with my (future) betta!

chickadee

That would be great!

Rose