I messed up.

[SomeHappyFish]

I don’t know what Red Sea contains, but sodium bicarbonate will slightly lower pH upon addition.

Thanks for the correction:)

 

[WhatCouldGoWrong71]

I raise my alk. From 7.8 to 8.7 all at once for 150G water volume maybe 1.1 dkh or 1.2dkh whats gonna happen now? Its a mistake. I was tired doing maintenance

I do that all the time. Zero issues at 1 dkh for me.

 

[ya_boii]

I think the Red Sea Alk is Sodium Bicarbonate but I'm not sure. Sodium Bicarbonate does raise pH for a while so totally normal.

Maybe someone else can confirm the ingredient

According to the MSDS, its sodium carbonate and potassium carbonate. Should raise pH slightly, which is pretty consistent with what OP says.