I sometimes mix some Dyna Gro Foliage Pro into the water for my water-grown pothos. It does seem to help them grow a little stronger and makes the colors a little brighter. I don't think it would hurt to add a weak solution of liquid fertilizer to your water grown pothos. Just because they can survive in pure water doesn't mean that they wouldn't benefit from having some nutrition.

The Miracle Grow isn't what "causes" them to rot. More likely a lack of aeration and possibly stagnation (unless you're changing the water very regularly).

Josh

Ideally, you should change the water about once a month and more often then that wouldn't hurt any. Change, not just top off. Even if you're using distilled or RO water, (Many bottled waters often contain mineral salts) you will still end up with metabolites from your plants and microbes that grow in the container.

In regards to bottled water. You need to be sure that it is either distilled water, Deionized water or water filtered by reverse osmosis (RO). If it does not show one of these three statements on the label it is probably just filtered tap or ground water with all the minerals left in. some bottled waters even have more minerals added to it after filtering.

I do dump the water, although maybe not enough. I wonder if they would benefit from foliar feeding. I have never heard of the Dyna Grow- I will have to look for it.Thanks!