Ammonia Spike? High Ph?

[attibones]

Usually my water levels and pH are close to perfect, but yesterday I was doing my weekly water changes in three of my tanks and decided to test the water since I had just purchased the API master test kit (so fun to use!). My ten gallon (currently housing fifteen shrimp, one molly) had a pH of about 7.4, ammonia of .25, nitrites were zero (I think?), and nitrate was at .40. I did my water change and added the recommended dose of aquarium salt, which I'm adding because I'm worried these parameters are stressing my fish. In my five gallon, I got almost identical results. PH was 7.4, ammonia was .25, but nitrites were up a little bit. .40 for nitrate. I added aquarium salt in this tank too. My poor betta, King, is currently living in a 1.7 gallon, but he's moving into the ten gallon as soon as I move my molly in with my other mollies. Either way, his tank had a pH of 7.4, ammonia at .25, nitrite at over 4.0 (!!!), and very high nitrate. I've never seen this happen before. I dosed him with aquarium salt (he's still healing from fin rot) and changed the water.

What should I do about my high pH?
For the very high ammonia/nitrite/nitrate levels, I plan on daily water changes. Is there anything else I can safely do?

I'm religious about tank cleaning. I don't know what happened.

 

[eaglesaquarium]

What dechlorinator are you using?
 
Don't play with the pH.  There is nothing wrong with the pH of 7.4, its fine for most fish and the livebearers actually prefer it.
 
 
Stick to a simple regimen of water changes until ammonia and nitrite remain zero for a full week again.  And increase water agitation to allow as much oxygen in the water as possible.
 
 
Not sure how your nitrate measured at 0.40ppm with the API kit.

 

[attibones]

No, sorry, the nitrite was deep purple, as in 5.0 (not .40, not 4.0) ppm. I'm using API stress coat to dechlorinate. My water never has chlorine, and I don't believe it does now.

Okay, so daily water changes, a good gravel clean, and daily testing. I'm going to move my betta as soon as possible, too. His tank (the smallest) was the worst. Hopefully I can get this under control soon.