Is there a "best timing" strategy to collect water samples?

Question

I mean in-terms of how often should you take samples from a water way/river/lake.stream to measure its quality. Is it better to do it daily or weekly or does it depend on the weather?

Are there other determinants that would determine how often you should take water samples to get the best results.

Answer 1

DJ is absolutely right.  In order to have a valid survey, you must get quite a few samples to account for variation due to rain and other factors.  You should note any differences when you do collect so you can explain them.

Answer 2

Do not so it after a rain. Take as many samples as possible so you can throw some out, also take them from numerous spots