Testing water that has been sitting?

[sunil6784]

Hi guys,

I am in the middle of my cycle, and I will be ordering my test kits soon. I usually stop at my LFS on the way home from work since my LFS is 45 minutes away right near my work. Can I collect water in the morning and bring it for testing 9 hours later? Does the water chemistry change at all making the results inaccurate?

[bertoni]

Nine hours is a long time. I probably would find another way to get the tests done. You could try on the weekend, I guess. Most of the ammonia-consuming bacteria in our tanks reside on surfaces, but I'm not sure what would happen to a sample after nine hours.

[disc1]

The pH is definitely subject to change, even in a short time.

Calcium, alkalinity, and magnesium would all be stable to test even days later, as would nitrate and phosphate.

The two you are most interested in during the cycle are ammonia and nitrite, and I don't know if either of those can really be expected to remain stable over that length of time.