My pool volume is very accurate, as I measured via water meter readings at time of fill.
So far, what I added, reflected perfectly in how the change in chemical took place. I am confident that for now at least, what I expect to see is exactly what I observe. Thanks for pointing out the details, I am tracking them to see if they do diverge. Then first thing I would suspect would be weakened chemical. That is something I can deal with easy though.
As to cold spells, get ready for one in about a week. I have been tracking it for couple days, supposed to drop our temps in Austin area, into mid 20s



for a couple days. From the 10th on for several days I expect arctic temps (well, arctic coming from someone living in TX).
For those of you not living in area, temps like that are almost guaranteed school closure, if we were not in covid times.
After that, I hope we dont have any more cold...grass here is starting to turn green, besides, I will have landscaping coming end of February to do sod, flower beds, etc. Then I plan to do some planting. Sure hope nature wont try to spoil it all.
For now still have trichlor in chlorinator, so I can bring my CYA (which is at 40 now), to about 45, maybe 50 max. However I do plan to use only liquid chlorine for normal maintenance, once CYA levels are achieved.
Maybe you can tell me what can make CYA levels drop as I have been reading in some threads (other than replacing water in pool)? Does it get 'used up'? Want better understanding for future. Thanks.
@ciaka you will want to keep CYA in 40-60 range for non-SWCG pool For southern Texas. Remember that we measure CYA in 10’s rounding to high side.
There are several things will affect the FC level and consumption. First is CYA level and amount of sun hitting your pool. Second is the true strength of the chlorine you use. Chlorine will degrade over time and especially affected by heat. Also your pool volume in Pool Math must be fairly accurate. So if Pool Math states to add 24 ozs and your FC does not raise to the calcuted level either your volume is off or your chlorine % is not equal to what your bottles states. So I tell you this not to frustrate you but to be aware of the variables and adjust accordingly as the weather warms. FWIW, I still think we have at least 1 more cold snap coming down through Austin and to Houston in February. Hope not but there always seems to be one in February.