I just did purchased some new fish for my 29 gallon tank and had my water tested while at petsmart..looked good except my alkaline was a little low. She suggested a 25% water change & bacteria suppliment and water conditioner. I also bought a moss ball. I did the water change (rinsing the filters in the changed water I took as I saw on a you tube video on water changes) and put stress coat in (lady at PetSmart said since I have that that would be good for the conditioner) waited 15 to 20 then put the bacteria suppliment in..got the new fish in nicely after acclimating them good. This was yesterday. When I tested this morning the hardness appeared to be closer to the 150 than the 75 mark on the chart. And the nitrite was around the light pinkish of 1.0 area...I am thinking this change is due to my water change...I feel let things be will it correct itself? get better? Thank you for any suggestions on the freshwater testings you may have.