Hello all, I've been lurking around for a while and this forum has been a very big help! I recently had to drain/dillute my 10000gal fb pool.. I became a high CYA victim 120+! and in the process became overrun with alage I tossed my trichlore pucks ( lesson learned ) and purchased several cases of liquid cholrine .. I started a SLAM on my pool.. My question is my test kit is a Taylor k-2006 and the CYA test is a turbidity test.. Right before I SLAM'd the pool I had a reading of approx 60ppm outside in sunlight, I brushed ( pool became pea soup) added 5 gallons of smart liquid shock I got at home depot and got the pool to settle at 40ppm FC this was at 7pm so around dusk I took another water sample and redid the CYA just to confirm my reading and the sample read a CYA of around 80 ish in kitchen lighting ( it had since gotten dark outside ) can the lighting cause this difference in the test? I can't restest becuase that used my last bit of test solution ? (I have some more in the mail due here in a few days ) since I'm unsure with this I split the difference and have been using the higher measurements for my pool SLAM... ( this morning I awoke to a clear pool to my surprise.. just had to brush the remaining alage off the pool walls clouding it a bit, FC was at 24ppm so I added 3 more gallons of chlorine to bring the FC to 52ppm)