Betta

Question
I asked a question earlier this week. I never knew that you need beneficial bacteria in your tank. I was given a aquarium (15-20 gallons) and thought it was ten. I was thinking about putting in the tank  6 Zebra Danios, a Siamese Flying Fox (I think that is what it is) and my Betta. As I said earlier I hadn't known about beneficial bacteria. Anyway the person that gave me the tank said to just clean the tank and leave the rocks alone because they had some bacteria on them. It probably won't be enough for my fish though. Should I just put 2 in at a time for 4 weeks or can I get some of this http://www.petsmart.com/product/index.jsp?productId=11147159 let it run until Monday (about 48 hours) and then add all my fish? How often should I test my water? And could I have any more fish than that? Thanks!!!!

Answer
Hi Elizabeth,
I apologize for being so late with this. There have been many complications on my end.

Even with beneficial bacteria supplements. I have found that it still takes some time for the tank to fully establish its 'biofilter' AKA the beneficial bacteria. Often the bacteria population will only grow to accomodate however many fish you have and the current 'wasteload' of the tank. So if you have say, only 2 fish in there. The bacteria will grow to handle just those two fishes waste load. So this is why its important to stock a tank gradually.... To give the bacteria time to catch up. Now some people are lucky enough to get ahold of a spare sponge filter that has been operating in a tank full of fish, then fishkeepers are able to just add the sponge filter that has a massive bacteria population growing in it and can handle a tankful of fish already -- plus add all the fish in at one time.

This is the only situation where I would feel comfortable recommending anybody to add a tankful of fish all at once.

I would simply give your tank time. If the tank was disturbed, drained down and moved around a lot then some of the bacteria in the rocks likely have died off.

If you see a lot of 'dirt' coming up from the gravel if you stir it a bit, then I would siphon some of that out to remove excess organics that are going to pollute the water.

So the bottom line is add 2-3 small fish. Let your tank run for two weeks (doing 20% water changes twice a week lightly siphon the gravel) then test your water (you can just bring a sample to petsmart but its great to be able to test it on your own) if the levels of ammonia and nitrite are - 0 then you can add 2-3 more little fish. Give your tank another 1-2 weeks and test the water again... Add fish if its safe. Patience pays off when stocking your tank. And you'll avoid a lot of the hardships that many people encounter simply for the fact that they stocked their tank too soon. Its important to remember you got a little ecosystem going on in your fishtank.

*Also, I wasn't sure if you are asking if you could add anymore than 2 fish initially.. Or if your current stocking scheme is your limit... If your tank is indeed in the 15-20 gal range you could have a few more fish than that. Depending upon the species, you could add 6 more small fish like tetras... Or add a couple of corydoras catfish either.

I hope this helps and good luck!
Susan~