I don't mean to be a downer, but I doubt you'll be able to out-compete for algae with plants in a brackish tank. What I'm trying to say is, yes you can grow something but nothing that will be using enough nutrients to make a difference with your algae. Certain plecos help with algae but they don't tolerate salt. Hornwort is good at sucking up nutrients but I don't think it'll tolerate salt, either. Stem plants grow fast if you have CO2, and that helps ward off algae, although I don't know of any stem plants that would tolerate anything approaching brackish salinity levels. CO2 alone without fast growing plants isn't going to help, either. All I can say is, there are some plants that would survive, but they are slow growing, even more so in brackish conditions, and will not be enough to help with the algae.
If you want planted for the sake of planted are are resigned to the algae issue, which might cover the plants as well, I'd say go for it anyways. I have done java fern in 1.005 and the original leaves didn't do so well and got holes in them, but after a few weeks, some new leaves started sprouting up like crazy from the rhizome, and they were beautiful. I ended up losing my puffer
, so that was the end of my experiment with plants in brackish. Keep the lights low and choose plants that don't need much light in order to help with the algae problem. To keep the waste from feeding it any more than it needs to, do as many water changes as possible and clean up the bottom when you do. Also, try not to overfeed. Keep your lights on for no longer than 10 hours a day, and if you can, set a break in the middle of the day, turning it off for a couple of hours. I haven't done this but I've heard a lot of people do to help give the plants a leg over the algae. I know it's basic and you probably already know it, but it's all I can think of to help.
