Safety covers
A solid safety cover anchored to the deck is the only cover type that carries a real safety function, and it is the only one worth considering if small children or pets are the concern.
Solar blankets, floating rings and mesh leaf nets are not safety devices. A child can slip under a floating cover and be invisible from the deck. Never treat one as a barrier.
Evaporation and water savings
A Central Texas pool can lose a quarter inch a day in July, and considerably more in wind and triple-digit heat. A solar blanket cuts that dramatically on the nights you use it.
The trade-off is labor. Pulling and storing a blanket on a full-size pool is a real chore, and a blanket left on during hot days can drive water temperature uncomfortably high and accelerate chlorine demand underneath it.
Liquid solar covers reduce evaporation modestly with no handling. They are not a substitute for a blanket, but they cost little and require nothing of you.
Heat retention
If you run a heater, a cover is the single biggest reduction in your gas or electric bill. Most heat leaves through the surface overnight, and covering the pool keeps the money you already spent.
Without a heater, a blanket in spring and fall can add several degrees and stretch your swim season at both ends.
Leaf covers during the drop
A mesh leaf net across the pool during the six worst weeks of oak and pecan drop can cut vacuuming, basket loads and staining more than anything else on this list.
It also keeps tannins out of the water, which is what turns pools tea-colored and stains plaster in the first place. If you have heavy tree cover, this is the cover to buy.
What a cover does not change
Covered water still needs circulation, sanitizer and balance. Chlorine demand drops under a cover, but it does not go to zero, and a covered pool that is not running can go bad quickly.
Covers also collect debris and rainwater on top. That water is dirty, and dumping it into the pool when you pull the cover undoes the benefit.
