Hello from New Zealand. I've been reading through Pool School and various other great articles and forum threads here at Trouble Free Pool. I've been going to the local Bioguard stocking pool store for years and simply followed the instructions on the print outs from there. Needless to say I'll be making some changes to that routine - primarily changing to use sodium hypochlorite rather than trichlor granules (Bioguard PowerChlor).
I've just finished a shock cycle after getting back from a 2 week holiday a week ago and finding the start of an algae bloom across the bottom and partially up the sides of the pool. That's was all sorted about 3 days ago, with the help of some flocking to help clear the water without needing to run the pump 24/7 for as long. I haven't put any additional chorine in while waiting for it to drift down but today I noticed a green tinge appearing on the floor of the pool where the water circulation might not be great.
UV levels here in New Zealand are very, very high over the summer and the sunlight periods are long. Up at 6am, down around 7:30pm. I'm wondering if that means I should look for a target CYA that's perhaps higher? I think these are the levels I should perhaps be aiming for but looking for advice here. With known numbers I can plug them into the Pool Math page with more confidence.
PH - 7.7
TA - 100 (is this still too high if moving to use bleach)?
CH - 100
CYA - 60
I've ordered a TF-100 test kit but it won't arrive for a while as I had to get it freight forwarded from the US. Prior to being able to do the testing myself I've got a sample from some test strips and the pool store.
Test Strips (Aqua Check)
FC: 3-5. Perhaps 4
PH: 7.8 - 8.4. Perhaps 8.0
TA: 120-180. Perhaps 150.
CYA: 100-150. Perhaps 120. Crazy high...
Pool Store (various reagents and color comparisons)
CYA: 59 (black dot test)
I've used the pool store numbers for Pool Math to start balancing the pool using a fresh purchase of 20 litres of 12% sodium hypochlorite. I have lots of evaporation over summer and lots of overflow in winter, which has probably kept the CYA in check since I've been using trichlor up until now.
Also looking for guidance on pump run time. Should it be based on how many times the pool water volume is turned over each day? Our pool is quite small with a relatively new 1.5HP pump. I can control the timings on and off easily with a Belkin Wemo in the pump power socket.
Thanks in advance for any advice provided!