Problems with cycling tank!!!

Question
I recently set up a new 210L tank. I had set it up for about a week and a half, fishless cycling. I then made the mistake of going to my local fish shop where they some Bactinettes which they said would cycle the tank in a day.
I stupidly took their advice and bought some.
The day after I bought them I took readings (Amonnia 0, Nitrite 0 Nitrate 10) so after more advice from the fish shop I moved my fish from my smaller tank into the new one (4 siamese fighters, 5 guppies golden nugget, red tailed shark and 4 cherry barbs).
They loved it but soon became quite quiet. I have checked the water (4 days after I put the fish in) and I now read Ammonia 0.25 ppm, Nitrite 0.25 ppm and Nitrate 10 ppm.
What can I do about the ammonia and nitrate, has the tank cycled with this Bactinette stuff, what can I do to solve this problem?
I am still running the old cycled tank to house some baby guppies and have taken the filter  out and squeezed it into the filter of the bigger tank........will this problem sort itself out, should I be doing more water changes (currently 1 a week) or will this mess the cycle process up (if the tank is cycling?) or should I put the fish back in the old tank until the new tank is definately ok?? It was an extremely stressful job catching the fish to move them in the first place and I don't fancy moving them back for their sake and mine!!!!
Sorry for all the questions but I have had these fish for nearly 2 years and am worried I am going to lose them.  

Answer
Leave the water for a while and keep monitoring it for a week or two. Basically you need to let it sit to create the balance  in the water, like a mini ecosystem. That way the good micro organisms will have time to build up. Once they have built up, they will help make your fish immune to infections. That is why you never remove 100 % of the water because it throws out the balance.

If you have live plants in there it will help a lot and get rid of some of the nitrate. So will gravel cleaners which sit in the gravel and suck out muck from there.

You can also get treatments to put the PH up and down, remove nitrate, etc.