We push the K2006 very, very hard for several reasons:

1. Pool store test are usually rather inaccurate, and strip based tests for CYA are horribly inaccurate. You cannot run your pool successfully over the long term without knowing what your CYA levels are. Remember, pool stores make MORE money, if your pool stays screwed up, so they have ZERO incentive to use more accurate, but more expensive test methods!

2. As CYA levels rise, you need chlorine levels to rise in compensation. (The Best Guess page, linked in my signature explains). The ONLY way to do this is use OTO (yellow drops) at ranges NOT shown on the test kit, OR to use the DPD-FAS testing Taylor developed, which is found in the K2006. Pool stores do NOT sell kits with DPD-FAS test methods.

So . . . get a K2006 and use it. Trying to answer the questions you have posted above, without the chlorine and CYA info, is a bit of a waste of time on both our parts. To some degree, what you've posted is just an example of what we've always taught: if you can get your water half-way right and KEEP it there, a month of normal care is much, much easier than even a single brief algae episode.