This will be the first time I've opened my pool after a winter hibernation. By now, especially after a spell of day time temperatures into the 30's the water is pea green. I had the presence of mind to clear up the larger debris whilst I could still see the bottom; not much, mostly birch and maple seeds and bugs. Partially drained it again to replace the under skimmer 3-way valve. Just refilled and set to chlorinate; I've avoided the temptation to purchase algaecide (at this point at least). I do have a fair amount of unopened clarifying agent (floc?) from an opening kit that was given to me by the previous owner of the pool, which I guess I could use if needs be, but I'll see how I get on with just chlorine.
Water chemistry, using Aquacheck test strip (probably not that reliable I know, but it's all that's available locally for FC and CYA) is
pH - around 7.2
FC - 0.0
Total alkalinity - around 80
CYA - around 30, maybe less (hard to judge).
So I'm planning to shock to 15 ppm FC. I do have 4Kg of 65% Ca-hypo to hand. Maybe use that for the initial shock (27oz: 0.77Kg) and then switch to 6% bleach as needs require.
I appreciate the need to keep the pump running 24/7 throughout the process, but two questions arise:
1. Would it be a good idea to have a (slow dissolve) puck or two in the skimmer or a floater to bring the CYA up? I have a load of pucks over from last season and don't really want to go out and buy stabilizer if pucks will do.
2. Unfortunately, due to work constraints, there wont be any one around during the daytime to attend to backwashes etc. If I start in the morning with the filter (sand) in Circulation mode, and then switch to Filtration mode in the evening when I can monitor the pressure gauge etc, should I still be OK?