Phals can be very forgiving when it comes to disturbing thier root for repotting. If you have bad roots then it would be a good idea to go ahead and remove them. just make sure you give the roots a good soaking before working with them. I always dust the cuts with cinnamon and let the plant sit around for a few hours to dry before I repot.

I'd say most orchids will grow in just about any of the regular mediums, so long as they've had time to adapt their roots to it. Those little red rock spheres are probably Hydroton or some sort of expanded clay pellet. I grow mostly in Hydroton. When i changed the medium to Hydroton, literally all of the existing roots died, but new ones came out which were thriving in the stuff.

The roots of phalaenopsis are green because they contain chlorophyll and help photosynthesize for the plant. This is why most people use clear/transparent plastic orchid pots, so the roots can be exposed to sunlight, along with the leaves. This helps them produce more food to grow stronger and healthier. I would say that it would be best to repot back into the clear pot it came in. Tho going up another pot size would be fine too. Phalaenopsis don't really get any bigger than they already are once they're full grown. If I were to recommend a pot, I would have to go with the Oxygen Core Dual™ Pots. These wonderful pots are sold online by RePotMe. I bought a couple of these pots to try out, and I loved them so much that I went and ordered some more. They sell them in a range of different sizes. The 5.5" pots are just the perfect size for most Phals. The inner net pot holds all of the media (I use 50% sphagnum moss & 50% bark/perlite/charcoal blend). This replicates the perfect humid environment for you orchid's roots, while giving them plenty of fresh air. All of my orchids love these pots. :) ^ You may notice the white nylon string that I have running thru the drain holes in the outer pot. I have them tied down the the wooden table so that they can't move. I live in Tornado Alley, and during Tornado Season, we can get some pretty fierce thunderstorms rolling thru. Before I did this, my pots used to get knocked around all the time. Which gets old pretty fast. This has proven very useful in keeping my 'chids secured and in one place. If I need to handle any of my plants, the I just remove the inner net pot(s). Just be careful if any new roots happen to be growing out of the net pot, because they can be easily broken.

First of all, put down the orchid and step away. You're killing it with kindness. If you want, just leave the phalaenopis unpotted until you get back from your trip. Orchids are tougher than you think. In my early years, I used to nitpick about every little detail about caring for my orchids. And I killed many of them in the process. I had to learn the hard way that they can care for themselves, just as long as you give them what they need, plenty of water and bright indirect sunlight. I've had this rescue phal sitting outside all summer long without a pot or any orchid mix whatsoever. It was potted up, but I didn't care for it because it lost all of its leaves and I thought that it was dead. But then I noticed this basal keiki growing off to the side of it. That's when I removed it from its old potting mix and left it completely bareroot. I did this because its roots can photosynthesize energy just like their leaves can, and I wanted it to gather as much energy as possible to help it grow. So its been like this all summer long. All I do for it is spray it down with a garden hose whenever needed. But now that it's growing its third newest leaf, I'll finally get around to potting it up today. The vast majority of orchids are epiphytes, meaning they grow up on the trunks of trees in the rainforests. Potting them up is more for our convenience than it is theirs. Dousing your plants with fungicides won't do it any good.