Algae is usually consider a nuisance. Although some would maintain soft green algae for certain fish to graze on.
The problem is that you can never be sure what algae you produce. I have yet to see any method where you get the desirable soft green algae & no bad ones like BBA, BGA, etc.
Personally, I would be happy to not see any algae, and if any fish requires algae to munch on, I would go buy algae wafers for them. If you really want algae, there is no need to "seed" your tank. Algal spores are in the air, you will get algae when tank conditions are right <Or "wrong" from our viewpoint!>. <Strong light, lots of nutrients - phosphates, nitrates ...>
Some people cultivate algae/microscopic life for frys (infusoria or green water). If you want to try growing algae, I would suggest doing that in a jar & not in your tank. .... Most of us spend lots of energy trying to get rid of algae. You don't want them to get established in your tank!