Please do not confuse the specificity of the results the pool store is giving with accuracy. There is no way to accurately test CYA much below 30 and a reading of "23" is really bogus.
Most time "cloudy blue" is the beginnings of algae starting to grow, but there are a couple of other possibilities also. To make the determination you really need your own test kit.
If you have read around here much you have probably seen that not much credence is given to pool store testing. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. In my case two different pool stores told me my CYA was "fine", around 70 or 80. When I tested myself I found it over 200.
To follow the pool care methods taught here you need to arm yourself with the knowledge and tools necessary to care for your pool.
The knowledge is condensed in the
Pool School link at the top of every page. It is a great community here, but we do ask that you read and try to understand the information being taught. Questions are always welcome and folks will try to direct you and teach you the methods.
The tools are not limited to the brushes, vacuum hoses and other stuff you use around the pool, but include the most important item - an accurate test kit. I recommend the
TF100 as it was designed for residential use and has more of what we do use and less or none of what we don't use often. You can buy a kit at a pool store, but again the pool store kits generally won't cut it. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. The TF-100 contains that test while very few other kits do. Think of it this way, do you see a doctor blindly prescribing drugs without seeing the patient or having tests run? Here at TFP we are going to ask for photos so we can see the condition of the water and are going to ask for a full set of test results.
The only other real option for a test kit is a Taylor K-2006. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.
I also have the
SpeedStir and
Sample Sizer. They speed testing and accuracy.