I understand your apprehension about draining your pool. It seems wasteful. But the water you let out isnt going to waste, it is going to get back into the water system somehow, either by you draining into a sewar, or into a creek that flows to a river at some point.
Since your pool is dirty, here is what you should do. Vacuum your pool thoroughly, with the pump set to waste. This will drain a lot of water out of the pool. Do a thorough backwsh of yoru filter, and that will drain a lot of water as well. After those two things, you will be close to losing as much water as you needed to in the first place.
Water is relatively cheap to replace, so it is not a big deal.
I just wanted to mention, that depending on where you live water can be
very expensive... In some cases, as much or more than the difference in bleach would cost. If you are home to test a few times a day, bleach won't cost as much as you might think.
Areas that have water restrictions are nearly always areas that have lots of sun and very high daytime (and nighttime
)temps. True, high CYA means slam level FC is higher,
but some of that FC is protected from the heat and sun by the dreaded CYA... So usually you lose less in between additions,
if you are testing and adding multiple times every day. Not to say algae doesn't take its toll on the FC level... But at least you're not trying to juggle the loss to algae
and the loss to the sun.
Of course, the best plan is to stay on top of things, so you won't have algae... But you know: best-laid plans and all that....
Plus, just try making the arguement that the water you are draining (or backwashing, or vacuuming...) from your pool isn't really going to waste.... The officer will at least get a good laugh while he's issuing the citation... And the surcharge that the water company tacks on to your bill will make somebody there smile. And then there's the little extra charge you'll see on your sewer bill, because if your water usage went up, it must be because it went into your sewer line. (And they won't waive the sewer charge here, we asked
)
You can buy a lot of bleach with what you'll pay in penalties, fines, and surcharges...
The cost to top off the water lost to evaporation is bad enough..... I love monsoon rains, because my pool gets filled back up for free.