Confused pool owner

[Upsman]

Opened my pool in March and got all my reedings in line.. I have a clorinator as my way of putting in chlorine.. My pool size is 18x36 Grecian style pool with a slope from 3ft to 8ft with slanted sides in deep end. In the deep end I have a 3person seated lagoon with swim out steps.. My water is clear can even see the screws in the main drain cover.. My problem is I have a low chlorine reading and can't seem to get it up to match my cya reeding.. Mu cc reeding is 0 to 0.5.. Is this because I heat my pool early due to our weather here in TN because it's still cool in March? Checked my chlorinator and its using chlorine because the 3 inch pucks are smaller.... My cya reading is 40.. I think I have a chlorine lock but not sure why or if slamming is required.. If slamming is why here in this case?? Just confused what to do to get my sparkling and glissining water back..




18x36 Grecian with diving board

Sand filter
speck pool pump 1.5 hp 2 speed
clorinator
jandy Laars pool heater
l have the Taylor test kit -k 2006

 

[Texas Splash]

I suspect because you have been using primarily chlorine tablets for daily sanitation, your CYA is too high and preventing the chlorine (FC) from being effective. Or, you simply have an algae bloom starting. Can you post a full set of test results please with your K-2006? I would also double-check that CYA, and make sure you test it outside only, and again only if the sun is out and bright today with the sun at your back. It effects the visibility of the black dot.

 

[Upsman]

Sorry my readings were
Fc 1
ph 7.4
alkalinity 90
cya 40

I do test the cya outside

 

[Texas Splash]

Based on your readings, I would have to say it's very likely you simply have an algae bloom beginning which is eliminating your already low chlorine even faster. Your CYA is fine, but your normal daily target FC should be 5, and never below 3. I suspect the FC got too low and now you need to "SLAM" (link below) to resolve the algae issue. Not the worse thing, but you will need to raise your FC to 16 and keep it there until you pass the 3 SLAM criteria. Read the SLAM page and ensure you follow those guidelines and you should be back to normal in no time. Any questions?

- - - Updated - - -

As a reminder, we use regular liquid bleach for a SLAM and prefer bleach for our daily uses.

 

[Upsman]

No questions but I will slam.. Thanks for being a sound board.. I know I raise it to 16 all at once then check it every hour to maintain 16 till it passes the overnight test.. Correct.. Just have never done a slam.. But no time like the present.. Thanks Texas Splash