Spring water doesn't necessarily have a low TDS (total dissolved solids) level, so as water evaporates, any dissolved minerals that might be in the bottled water get more & more concentrated .......... unless you're changing the water regularly.

I don't grow anything in water, but if I did, I think I'd use my R/O water + a fertilizer with all essential nutrients (the MG lacks several, including Ca and Mg, secondary macronutrients both, that might or might not be found in adequate measure in your tapwater or mineral water), like Foliage-Pro 9-3-6. That at least saves you from trying to find out what's in your tapwater or in the spring water you're using.

I'd make it a point to keep the plant in a weak fertilizer solution at all times, and I'd rinse the roots in tapwater and change the water in the vase weekly. If algae decides to become an issue because of the light that passes through vase walls + the fertilizer, I'd switch to an opaque container.

OR, I'd forget all that and pot them in the 5:1:1 or equal - at a minimum it would be a soil you can water to beyond the saturation point w/o concern that root function or health would suffer due to extended periods of soil saturation.

Al

Pardon me, but is that really a Peace Lily? Doesn't look quite right to me for PL, the white Spath doesn't look quite right. The leaves remind me more of Anthurium.

I keep far too many plants in water, and, as Al points out, you can keep them in very, very weakly fertilized water. I use a water soluble MG in a spray bottle, heavily diluted with water, on the leaves as well.

Karen-

I'm 100% sure it's a spathiphyllum-the spaths did look sort of twisted but the spadix was definitely that of a spathiphyllum's. It was also sold as "Spath in vase".

Here's some more pictures-

Al-Thanks for your reply! I'll make a note to refresh the water more often and to add maybe two drops of the fertilizer each time I change the water. After I finish up the bottle of 12-4-8 I plan on ordering the Foliage Pro from Amazon.

Lauren-It's good to know that it works for your water-grown plants! I hope my peace lily makes a full recovery once I clean it up and give it some fertilizer.

I'd like to reiterate Al's point about changing the water. A lot of people, my mother is one, believe that you don't need to change it, you can just add to it. It needs new water regularly. They thrive on that and it prevents algae buildup. And you really, really have to be mindful of not over fertilizer. Every now and then, I squirt a bit of hydrogen peroxide in some fresh water and leave off the fertilizing.

I grow, as I said, waaaay to many plants in water, but one thing I think is important is keeping their environment fresh and clean.