^to my mind, since you'll want to lower the cya anyway, a partial drain, eg 30%, would be worthwhile. But that's your call.
What's important is that your FC level at Slam matches the Fc:cya level in the chart (see my sig) ...or is slightly above. Any time you drop below that ratio you are in effect, wasting bleach -- aka taking a knife to a gun fight
That's because algae can grow faster than inadequate levels of chlorine can kill.
So whichever way you go, don't go "halfway" -- slam it and bring the FC up frequently enough to remain above your FC evil as often as possible. Precision is your friend
Re: wife and phosphates, ask her if she's rather you killed an attacking zombie or just tried to starve it
Maybe that analogy will get through. Dead algae don't eat. The goal is to have a compete dead zone by having completely sanitized water...through correct FC! And remind her that algae isn't the ONLY thing you're killing with properly sanitized water...you're killing bacteria and fungi as well.
I have uber-high phosphates 100 times higher than the pool store would advise, (because I am on well and use metal sequestrant) and I have not had to address a spec of algae since recovering the swamp and following the TFP method.
What's important is that your FC level at Slam matches the Fc:cya level in the chart (see my sig) ...or is slightly above. Any time you drop below that ratio you are in effect, wasting bleach -- aka taking a knife to a gun fight
So whichever way you go, don't go "halfway" -- slam it and bring the FC up frequently enough to remain above your FC evil as often as possible. Precision is your friend
Re: wife and phosphates, ask her if she's rather you killed an attacking zombie or just tried to starve it
I have uber-high phosphates 100 times higher than the pool store would advise, (because I am on well and use metal sequestrant) and I have not had to address a spec of algae since recovering the swamp and following the TFP method.