My moderately planted 30 gallon tank has been established for a month (finished cycle and fish in mid-May, plants in since 4/30). All has been going fantastically and I just started with ferts a few weeks ago.

Unfortunately I started with gravel and added corys, and at the time I had no idea corys don't prefer or generally do well on gravel, so I'm having a huge fit of guilt and am considering the switch to sand.

A few questions:
• how badly should I expect my plants to fare with a switch like this to sand? (I have Spiralis, moneywort, wendtii, and a sword)

• what kind of special care would I need to take with them if I do decide to go through with this?

Hm... from my experience plants don't really care that much about substrate changes. It's the fauna that have issues with bacterial infections and spikes from the substrate change.

I would just move all the plants, decorations, and fauna into a holding bin. Use tank water to keep the parameters the same. Then scoop out all the gravel, place in the sand, then put everything back in. Use as much of the old water as you can to preserve parameters.

+1..

Put everything in rubbermaid tote with filter and heater on if u can so it gives you a while to do what you gottta do. Scoop out old, rinse new substrate with just cold water before and put in tank. I just add a bit of water conditoner to be safe since your rinsing with tap.
Whats nice about the change is it lets you easily rearrange your plants