Nick
My vote is yes for the autofill, but have the plumber install a valve so it can be turned off in case the autofill sticks.
A drain that maintains the proper level of water is useful if you live in an area with frequent rainfall.
Other plumbing ideas include an outdoor shower or at the very least have your plumber install the piping for it now.
Have your plumber install an outdoor faucet near the pump/filter area.
These are all inexpensive additions now that will make your pool easier to maintain.
CHEM GEEK can provide more information about dealing with Iron in your water, but here are a few general observations.
Staining may be seen with iron levels as low as 0.3 ppm
Water softeners can remove a limited amount of dissolved Iron from your water.
Depending on the Iron concentration in your water it could stain the white fixtures in your pool like the skimmers and the return eyes.
If PH gets above 7.6 it seems to cause more staining.
If you start to notice staining and you are keeping your PH below 7.6 then you may need to add a sequestering agent monthly.
The sequestrants with HEDP work well to prevent metal staining, slows calcium scaling and have a minimal effect on chlorine.
If you have a SWCG be sure to use a sequestering agent that is compatible with salt.
Taylor makes an excellent kit that can measure Iron concentrations from 0.2 to 2.00 ppm and is accurate to 0.2 ppm.
http://tftestkits.net/K-1716-Taylor-Iron-Test-p30.html
Order the TF-100 kit and take control of your water chemistry right from the start.
http://tftestkits.net/TFTestkits-TF-100-p4.html
