Water Testing Question - can it sit?

[bikerfish]

I try to test my water at the same time of day, so that anything affected by lighting or whatever will be reasonably consistent. But, sometimes it doesn't work out, because I have to leave, or don't have time that day, or whatever.

Is it a bad idea to just take some sample water out of the tank and hang on to it to test a few hours later? Will it change significantly?

Or is it pointless to try to test at the same time in the first place? I'm sure I heard that you should be consistent somewhere, but I could be wrong.

If I could just save the water, I could just grab a sample bottle at 7pm, and then tested it when I get around to it.

Thanks

 

[Serk]

Just my opinion, but other than pH and temp, I don't think it matters all that much as to time of day...

Or to put it another way, I'd rather have a fresh sample of water at a different time then a stale sample taken at the same time, if that makes sense...