Converting freshwater to a reef tank

[sse1990]

As the title says, I’m thinking of converting my 37 gallon bowfront tank into a reef tank. Now that my 90 gallon mixed tank is moving along, I don’t have as much interest in freshwater.
I currently have a Fluval 307 canister filter on it.
Other than getting a proper light and a couple of power heads, is there anything else I would need for this tank?
Most likely only going to keep a couple of fish in it to supply the phosphate and nitrate.
I’m looking at making it a softie thank and keep my 90 gallon for my other corals.

here is the tank currently.

 

[jnava19]

Probably add an ATO system to keep salinity stable.

I was thinking the same couple months ago, but decided to keep my freshwater, just replaced all decorations that looked fake and added real plants and rocks, piece of wood, couple snails, and now I think really looks nice, wish I could easily change the gravel, but now looks much more natural and to be honest, I also run my freshwater with a canister, and when I started the saltwater I did with a canister, and maintenance was too much cleaning it almost weekly, so I ended up switching to sump quickly. The freshwater I just top off water every month, cleaning canister probably every 3 month, and water changes, every 3 month as well. Just need to clean maybe every two weeks or so extra algae from glass that snails don't do. I really do very little maintenance on the freshwater and they do good.
Some of my fish which are also same from your picture (glofish tetra) have been on the tank for 3yr already.

 

[01xp]

When I switched from fresh to salt I reused everything beside the gravel. Switch that to sand and your good to go let it cycle and slowly switch to live rock