Watering Poll

Rainwater.
Collected from my roof(roof tiles are slate so basically inert) , i have about 450litres capacity(100 gallons roughly).

Rain water? What's rain water (in northern Florida)? The well water in my new north Florida location is 250+ TDS, pH 7.8 - 8.3 with high [iron]. Not wanting to use Na softened water, I used the well water. After a year of poor plant growth, some of which might be attributable to water quality (hi pH and TDS), I switched to KCL in the softener and began using softened/treated water. I also purchased a pH meter and use "Downer" to adjust the pH into a range (5.8 - 6.5) suitable for the plants to make better use of available nutrients.

I have a small 25x10' enclosed green house with about 150 generally hearty plants in only a few genera (nothing exotic). Even having switched half the collection to S/H, I still use 25 gallons of treated/adjusted water at a clip. In between waterings and cooling is done with straight treated water.

If the collection were smaller or I was indoors, more expensive water alternatives might be an option. I tend to grow what grows for me. As my facility conditions and techniques get better, maybe the collection will diversify accordingly.

Rainwater when possible, otherwise its the water from the tap outside.
Connie

I know your list couldn't include every possibility, but what about softened water now that KCl is available many places? I have well water as house water at the new place. The TDS is too high (250 plus) and the Fe is in the [colorful]. So treated, softened water was the only way to go with out resorting to the expense and ongoing complexities of RO water, which for 100 plus plants was out of my budget & patience.

I use rain water as often as possible, but tap when the weather is dry. I also have a small pond that I "steal" water from every so often. I think that the natural water is just better, I can't offer any scientific proof-but things just seem to be more responsive to rain or pond water over the tap.