adding new fish

Question
HI there, we have had a 10 gallon tank now for about 6 months and we had two goldfish in it.  One died because he got got in the filter.( He was a black googly goldfish) So we noe have one goldfish and just added two dalmation fish, two small albino cleaning fish and three guppies.  The pet store told us that they were all compatible and that we could add them all at once.  Now my tank is very established and I do a 25% water change every month and clean the gravel and glass at the same time.  the goldfish we had during the 6 months were very happy and never sick.  My question is do I need to check the chemical levels of the water now that I that I have added more fish?  In the past I have only checked the ph and it has always stayed the same around 7.0.  I know that as you add the fish that the levels will change as the tank acclimates.  Another question I have is are the fish going to be quite active as they are getting used to their new home?  What sort of behaviour should I be watching for?  Thanks for your time, Maria Foster.

Answer
Hi Maria,
Thank you for your letter. My aquarium care system is posted here:
http://steamboats.com/aquarium.html
The main thing to watch out for is over feeding. Also, if you use the product, Cycle, friendly bacteria, in the water, it will prevent problems.
Please read and print out the instructions for future reference.
Write back if you have any questions.
Nori