New member with new tank

[Mondaygirl]

Hi all! I'm new, and so is my 20 gallon tank. It's been running for about two weeks. I let it run without fish but with the liquid bacteria from Marineland (I think?) for 4 days, and then added 4 platies (2 male, 2 female) and a tiny little red shrimp. After a week I had the water tested, and the guy at the LFS said the levels were great and the water was crystal clear. I added 3 live plants as well as 5 cardinal tetras. The tetras have only been in there for 2 days, but I swear they have doubled in size already! The platies are so much fun to watch, and the tetras are lightning fast. I just love watching the goings on. Next on my list is a water testing kit; I don't think the LFS would be happy if I return weekly to have my water tested without buying any fish!

This is my tank! The reddish fuzzies on the right are two of the platies riding the bubble stream up, after which they swim back down and do it again. Any tips, hints, and pointers would be appreciated by this newbie.

 

[Toney]

Howdy

 

[Ch4rlie]

Nice little set up.

Though I reckon am goign to be bearer of news you may not want to hear, I do not think you have cycled your tank and filter to deal with the bioloads from the fish you have.

Though only a few fish in a 20 gal, may be ok for a while as it would take some time for the ammonia / nitrite to build up to be of any harm to these fish in the tank but I would recommend you read these articles -

http://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/

Then perhaps reading these will inform you a little more -

http://www.fishforums.net/threads/rescuing-a-fish-in-cycle-gone-wild-part-i.433769/

http://www.fishforums.net/threads/rescuing-a-fish-in-cycle-gone-wild-part-il.433778/

A lot of reading but worth doing so and helps you to make a more informed decision if indeed you have not cycled your tank. Marineland bacteria starter is probably not going to work (you may get lucky but doubtful).

Couple of options of pretty reliable bacteria starter that may help your cause is either Tetra Safe Start or Dr Tim's One and Only Nitrifying Bacteria
(both of these have the correct types of bacterias needed and both formula were made by the same scientist)

 

[Mondaygirl]

Thanks! I read the provided articles (I had read the first one already, but not the rescue ones). I used the calculator mentioned in the third link, and my NH3 concentration is 0.0042 ppm. This afternoon the ammonia level tested slightly lighter than 0.25 on the API test kit, so between 0 and 0.25. (I tested both before and after a 25% water change, and the level before the change was 0.25, which is why I did the water change).
Nitrite and nitrate both tested at 0, and the pH is 7.6.
The LFS assured me that the liquid bacteria would do the job of starting the cycling process, but they advised to slowly build up the population in the tank so as not to cause sudden spikes in ammonia and/or nitrite levels.
Should I at this point add one of the recommended bacteria products? Or continue to monitor levels and do regular water changes? I feel like the tank is slowly going through the cycling process and all is well, but I've read enough by now to know that a gut feeling isn't a reliable source. Thanks again for your reply and advice!

 

[Mondaygirl]

I thought I'd add that I have just tested my tap water and it shows the same ammonia level as the tank water, between 0.25 and 0.