I bet if you take a nice white bucket and scoop water out of the lake it will appear "murky, it's sort of clear but brownish" also. Everyone has pointed you in the same direction, filtering and chlorine will clear up the water. Just like stuff lives in the water in the lake (algae) it is now living in your pool.
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. So we would not recommend taking a sample down to the pool store for testing. They are going to tell you what we already know - you got lake water in your pool. Then they are going to sell you lots of "stuff" to lighten you wallet. We do things differently around here. We believe in accurate testing and only adding what is necessary to fix the problem.
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 - one of the
recommended test kits. 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. All these kits contain 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?