How many fish to add to new aquarium

[St. Louis Cardinal Tetras]

Hi, I was just wondering how many fish I could put in my new 29 gallon aquarium. I am going to have established filter media in the tank so there will be BB present. The list of fish I have that are going in this tank are cardinal tetras, gold dust mollies, fancy guppies, a pleco or two, and Corey cats. I was thinking about putting one or two of the tetras or guppies in but was wondering if I could get away with putting 6 of the cardinal tetras in as I know you should keep them in groups. Also, which fish is the hardiest? This is my first tank but I completely understand the nitrogen cycle and how to test water and everything. 

[Brandy]

Start slow.

The guppies/mollies and the cardinals typically want different water hardness, so you may want to check yours and aim for the middle. You can put in a group of small scchooling fish at the same time and they will do better than just a few, but don't put in the whole community at once.

[Maggie]

I started with 8 juvenile rasboras in my pre-cycled 45-gal tank without any problem at all, then added 6 otocats a few weeks later, and 12 more juvenile rasboras a few weeks after that, and lastly, 2 juvenile angelfish. I've also read to add smaller fish first so that the larger ones don't have an established territory and possibly attack any newcomers who don't yet know the "lay of the land".

[Patrick_G]

I’m thinking the number of fish will be fine, but buy two-three batches over time. Maybe Cardinals first them bottom fish then livebearers. 

[St. Louis Cardinal Tetras]

Thank you guys for the advice. I just tested my tap water. My ph is around 7.5, my general hardness is 1.7 dGH

and my carbonate hardness is 2.2 dKH. So I’m thinking about getting some wonder shells or something. I didn’t know my water was so soft. I think I’ll start off by adding 6 guppies and test the water everyday. 

[lefty o]

half dozen cardinals is a good start. add them, then give it a week or two, then add something else.