Hello Heidi, and Welcome to the Garden Forum!
I'm keeping Phalaenopsis orchids in Central Arizona. They've become my favorite houseplants. Mine are in bark, in clear slotted pots. They're doing well, and bloom every year.
Growing them on mounts would be more natural, but the humidity here is very low. In bark, the aerial roots tend to shrivel and dry up, so I haven't even tried growing with no medium.
I'd be very interested in seeing a picture of your 3D pots, and how you have the orchids in them. Please post some photos if you can.
If you haven't already, I suggest having a humidifier close to the plants. Misting and humidity trays don't really do much, even a small humidifier will help more.
Epiphytic orchids in nature have to very quickly absorb water and nutrients from whatever comes their way. Picture a brief summer shower in the rain forest. I think you'll get more benefit from your fertilizer if you use it first, instead of loading the roots with plain water first. If you're using a dilute solution, it shouldn't burn.
I'm in the weakly/weekly camp, I soak them with 1/2 strength fertilizer in the water, every week. Hopefully you'll hear from people with mounted orchids, who can advise you. I've been using Jack's Orchid Special, but will be trying a K-lite formulation this year.
This forum is usually pretty helpful and friendly, I'm sorry for the various previous remarks directing you elsewhere. Just FYI, there is a dedicated orchid forum, also a thread in the houseplant forum for orchids. For an orchids-only intensive, I also recommend Orchid Board, lots of friendly experts there. You might look into the Utah Orchid Society, sounds like they might be in your area. There's nothing like getting local advice!
Welcome, and please send on some pictures, I'd really like to know more about those 3D printed pots.
