In the 60-80 CYA range, why are the Minimun and Target FC ranges much lower for SWGs than non-SWG pools? I've only had my SWG 2 weeks, but I'm getting algae at the lower target range. I'm in NE Florida and we've been getting monsoon rains and perhaps that is influencing the water balance.
Chlorine/CYA Chart
- Thread starter jagfan
- Start date
The FC levels for SWGs have been determined by trial and error. They appear to work for most people. We don't know why the level is lower for SWG pools than for other pools, all we know is that it works. I have heard a couple of different theories, but none of them are completely convincing.
Some pools require higher FC levels than the minimum that appears in the chart. That is why we express it as a range, between the minimum and the target levels. Also, keep in mind that you should test the water in the early evening, which is when the FC level is normally lowest, to be sure you are not going below the minimum at that time.
When you have large storms, it is easy for your FC level to go below the minimum for a while during the storm. if that happens, you can get algae at that time. SWGs tend to fight with algae, such that the algae never really gets going but also never really takes over. You need to make sure the algae is completely killed, by carefully shocking your pool, before you go down to the low end of the recommended range.
Some pools require higher FC levels than the minimum that appears in the chart. That is why we express it as a range, between the minimum and the target levels. Also, keep in mind that you should test the water in the early evening, which is when the FC level is normally lowest, to be sure you are not going below the minimum at that time.
When you have large storms, it is easy for your FC level to go below the minimum for a while during the storm. if that happens, you can get algae at that time. SWGs tend to fight with algae, such that the algae never really gets going but also never really takes over. You need to make sure the algae is completely killed, by carefully shocking your pool, before you go down to the low end of the recommended range.
If after shocking and making making sure you measure the FC when it's lowest (just before your SWG & pump turn on again, either at night or in the morning depending on whether the pump runs at night), then please let us know as much as possible the actual CYA and FC levels. This helps us adjust our recommendations if we see a pattern. Is the algae regular green algae or yellow/mustard algae?jagfan said:
Richard
It's green algae. Am unable to obtain readings after today as I ran out of FAS-DPD reagent. Will order more tomorrow.
Similar threads
