Assistance choosing fish for new tank

Question
I am a beginner and have just bought my first tank. Its 70litres (18gallons I think) but I dont fill it right to the top.  I have a cool water setup and have already put the gravel, pump and water in for the tank to run fishless for a few days. Its been running for 3 days now and I would like to get fish tomorrow but am not sure about what to get and how many of each kind. I dont want fish that omit too much waste and I want them to be nice to look at. I have done quite a bit of research and have these options on my list: Cherry Barbs, Glowlight Tetras, Harlequin Rasboras, White Clouds, Zebra Danios, Fancy Guppies and Ghost shrimp. I would like there to be a bottom feeder as well and therefore think the Ghost Shrimp would work. I would prefer having smaller fish so I can have more in the tank. Please advise me on which fish and how many of each to choose? Thanks so much!

Answer
Hi Kim,

First of all, when you get your first batch of fish, DON'T add them all in one time! First, add 2-3 hardy fish, like Zebra Danios. This is because your new tank is not yet 'cycled', or in simpler terms, it has not yet established the beneficial bacteria that remove fish waste. During this first period, toxin levels are extremely high in your fish tank, and only hardy fish can survive during this period.

You mentioned that his was a cold-water setup. This will NOT work for any of the fish you mentioned except the White Clouds, Zebra Danios and Ghost shrimp. Unless you want to only have those three species in your tank, I recommend that you get a heater. A 100-watt heater would be most suited to your setup. A heater, if you get one, should be set to 78F.

I would like to point out that all the fish above are peaceful community fish, and except the Guppy, they are all shoaling fish. This means that they must be kept in a group of 5 or more. If they are not kept in groups, they will be stressed/unhappy and may not eat, become sick, and they will definitely not show off their best colors. So, this limits your tank to two species plus Ghost Shrimp.

It's really a matter of personal preference of what you choose. All of those fish are great with each other in a tank with a heater, except for a couple points:

-Tetras are stressed by super fast fish like Zebra Danios.
-Livebearers like Guppies generally prefer more alkaline water than Tetras.

So, here's some ideal stocking plans:

-6 Zebra Danios >>
-6 Cherry Barbs or White Clouds

OR

-3 Fancy Guppies*
-6 Rasboras
-5 Zebra Danios or White Clouds >>

OR

-6 Glowlight Tetras
-6 Rasboras or Cherry Barbs >>

If you do not have a heater:

-6 Zebra Danios >>
-6 White Clouds

Ghost shrimp can be added to ANY of those setups.

Remember to add only 3 fish during your first stocking. These fish will be the only fish in the tank for the first month! They will be hardy fish, and I've marked the hardiest fish in each setup with a >>.

During this month, perform 20% water changes every other day to keep down toxin levels. After the first month, you can add fish slowly, about 2-3 per week. You can also switch to a normal water change routine of 20% of the water changed once per week.

Good Luck, and Happy Fishkeeping!