My 55gallon top tank has lots of brown and green algae.. but theres also purple in there what type is this? This tank is fresh water.. theres a oranda in it.

Could it be black brush. It looks purpley when young and with the lights on.

I have no clue to what that is(LOL) is is normal and safe??

Yes its safe. They are all safe as far as I know. But this is one of the hardest to get rid of/scrape off. It grows short never very long and thrives at a pH above 7. That's all I can remember. Oh and I think there is only one algae eater that will eat this one.

thankyou.. I will just leave it alone.. its only on the back of the glass in a small section.. do you know what helps this type of algae grow or where it comes from?

Two things that encourage algae are lack of dissolved oxygen in the water and a lot of bright light in combination. If you have lots of of plants, esp fast growing ones they will compete for the oxygen with the algae and almost always win so its a question of getting that balance of oxygen/light and plant life that suits your size set up

hmmm well i have no plants and theres plenty of o2.. the lights are kept on for atleast 14 hrs though.. maybe that's why..