How often to run various tests, and how long do you run your filter?

[waterbear]

But the question was "how often do you test"

I viewed the question as one with a 'universal you' as in meaning "How often should these things be tested" and not as how often does each individual answering the question test, which is not going to be valid for the OP as your case clearly demonstrates.
Personally, I know my TA and CYA stay stable because I have a cart filter so I only test those evey few months but I do test my CH every two to 4 weeks because the level tends to drop faster than the previous two parameters (I have soft water and a fiberglass pool and have seen first hand that higher CH does help prevent stains in fiberglass.) However, this also is not pertinent to the OP.

Ditto for how long to run the pump. How long either you or I run the pump doesn't matter but the OP will need about 10-12 hours a day with her Intex pump/filter on a 5 k pool.

[CarlD]

OK, I'm going to take the company line here and NOT give out all the "exceptions".

1) Test your pH and chlorine once a day, best at sunset, and add chlorine, borax or acid as needed. If your chlorine runs in the 5 or less range, you can use and OTO kit and get the TC level.

2) Run a full suite of test, (FAS-DPD, pH, T/A, CYA) once a week and record the results.

3) Calcium Hardness: If you have a concrete pool, check it once a week. If you have a vinyl pool, check it at least twice a season, once when you open, and once about mid-season.

4) Metals: Only if you suspect metal contamination.

5) Phosphates: Once every 15 years--or less.

6) Pump/filter time: You should run it 10-12 hours per day, but you can set your timer to run part of that during the night.

All the exceptions are for people who really know their pools, know what corners they can SAFELY cut, and what they can't. Until you know your pool, this is the easiest way to do AND not have problems.