Hi bfloboblo. Welcome to Fishlore:
If it were my tank, I would store the sand and protein skimmer (
SW sand substrate could already have unhealthy levels of
calcium and other trace elements for
FW plants, the skimmer is of no use in FW) for a future SW set up.
I would use a nutrient rich substrate (e.g. Eco-Complete or alike either as sole substrate or mixed with natural river sand).
The lights you already have (replacing actinic lamps, if present, with 6,700 or 10,000 Kelvin CFs) should be all you need for planted tank.
I would use the UV-C Sterilizer with a flow rate of 40 to 50 times the wattage (e.g. 200 to 250
GPH if 5W) for
algae control.
I would use the Magnum without the bio-wheel assembly if going with CO2 injection or leave them if using Flourish Excel as organic carbon source. I would experiment with the HOT Magnum.
Take your time reading around and enjoy the planning. A planted tank takes some effort that surely worth it. All my tanks (except hospital) are planted, including my Nano reef.
Pepetj
Santo Domingo