Brown algee, chemicals and figure 8 puffers???

[Mandalynn87]

Hello
Have a figure 8 puffer. His tank is cycled but is new. ( we moved the media and some gravel from his old tank into his new tank) I've done daily testing for a while. Weeks and we are stable. Ph 7.8 to 8 ( hard to tell witch) 0 nitrates, nitrites and ammonia. Hard water. Has some new plants in there that he is tearing to shreds.
Now ive got a brown agee problem. Not to terrible. But its on the gravel and plastic plants and coral rocks and decor.

I heard puffers are scaleless, and therefore more sensitive to chemicals. So im afraid to use the chemical algee treatment i bought.

Is this true? Are there other ways to get rid of it. It's all over the small gravel substrate ( I would like to switch to sand but not in the near future) so "scrubbing isn't an option. Plus I tried a new toothbrush and it didn't work well on the Coral, and only soso on the plants and decor.

When I switch him to brackish will the algee die? I'm gonna go low brackish , like 1.003 and then if my plants survive ill stay there, if they die, then 'll go to 1.008

[Pufferpunk]

library/water-filtration/brownalgaediatoms/