I need 30 amps in a single room to run vegetable grow lighting. How to accomplish?
Since you've got conduit, and since most lights are not designed to be directly on 30A circuits (normally in the US designed for 15A or 20A circuits), run two 15A or 20A circuits through that conduit instead. It will take more spaces in your panel - if that is a problem, upload a picture of the panel for help.
Note that 2 x 15A is perfect for the lighting. Each 15A circuit should have no more than 12A of continuous use. In order to have additional stuff on the same circuits, you would need to bump up to 20A circuits - that would give you 5A total, 4A continuous additional on each circuit. But if the lights are hard-wired and the other items are plug-in then you really should have a 3rd circuit for the receptacles, as you should not put receptacles on a circuit that has hard-wired loads &gt; 50% capacity.