I always understood the main issue was CYA build up over time and the only way to reduce CYA was to drain water and replace it.
For the last 10 years or so our pool has had a CYA of about 40 - 60 (best guess as the test is not really easy to read). We did liquid chlorine in the summer (swim season) and water was perfect and no algae blooms. In the winter we use tabs as solar is off and pool temp low. Always a little surprised each spring that the CYA wasn't higher after using tabs - but everything good.
This year we have had very high liquid chlorine usage (which is getting very expensive with the current cost of chlorine) and testing CYA it seems maybe 10 - 20 (again the I find the test very hard to read to get an accurate result).
Could we really have lost CYA like this? Pool is never drained (on a well and it would be prohibitive to try to refill) just topped up during the summer to replace evaporative loss (but the CYA should stay in pool - correct?)
Are there any more accurate CYA tests than the black dot test? A little reluctant to add CYA until I know it is really low as it will really be hard to lower it if it gets high.
Pool still looks great - but if CYA is low I guess even low levels of chlorine would be working....
For the last 10 years or so our pool has had a CYA of about 40 - 60 (best guess as the test is not really easy to read). We did liquid chlorine in the summer (swim season) and water was perfect and no algae blooms. In the winter we use tabs as solar is off and pool temp low. Always a little surprised each spring that the CYA wasn't higher after using tabs - but everything good.
This year we have had very high liquid chlorine usage (which is getting very expensive with the current cost of chlorine) and testing CYA it seems maybe 10 - 20 (again the I find the test very hard to read to get an accurate result).
Could we really have lost CYA like this? Pool is never drained (on a well and it would be prohibitive to try to refill) just topped up during the summer to replace evaporative loss (but the CYA should stay in pool - correct?)
Are there any more accurate CYA tests than the black dot test? A little reluctant to add CYA until I know it is really low as it will really be hard to lower it if it gets high.
Pool still looks great - but if CYA is low I guess even low levels of chlorine would be working....