new fish for 20 gal

[spAcE mOnkEy]

i was planning on makeing my 20 gal tank a heavialy planted tank. i want to have a school of about 10 cardnal tetras and some other random tetras. i have never really kept that many tetras before and i would like to know the type of water they like. i know they like low ph around 6.7 and soft water. does anyone know how to make my water soft? i also would like to know if they live with some salt in their water, i moved my puffer from there and he liked brackish water so its kind of brackish now. i also would like to know if these fish would do good in that tank, here is my plan for the fish that would be in that tank:
2 honey gourimis
1 zebra diano
1 guppy
1 spotted rapheal
8 cardnal tetras
2 glass catfish
1 pleco
please tell me if this would be over crowded or if these fish cant live together
thanks,
space

 

[Ben]

i rekon ur tank will be fine except glass fish are ment to be kept in schools ad if not they die.

 

[Sorrell]

Danios and guppies need to be in schools too.

 

[Lateral Line]

You would be better off changing the water out, most fish, even those from salt free environments can tolerate a very small amount of salt, but brackish is quite different. You also mention plants, there are very few salt tolerant plants. Strip the tank down and re do it, you'll save yourself a lot of trouble.

Other then that, unless you are really sure what you are doing, I would advise against trying to soften your water or adjust it's pH. Most of the methods available can lead to very unstable water with big pH swings, so people buy pH stabilising chemicals which are full of phosphates so encourage an uncontrolled algae bloom.

Zebra Danios are very much a shoaling fish, kept individually or in pairs, they can become quite aggressive. Glass catfish again prefer to be in a larger group, as do guppies.

You'll need to be careful which kind of pleco you get, (they really do not take salt well incidently), as most grow very large.

 

[Cheese Specialist]

glass fish are ment to be kept in schools ad if not they die.

That's not exacty true. Some people have kept even lone glass cats ok but many keep them in pairs. I have 2 in my largest tank and they are very active.

However, I think it is important to keep them in even numbers. They tend to pair off and one will be left alone.