hey there Lynrd ! turns out algae is not a bad sign, rather it's the sign of a healthy organic system. You can always add beneficials to stay organic like Great White. None the less HO2 totally does work for exactly what you're looking for and it really wont be that bad for the organics, simply it will kill off most benefical bacteria so you end up needing to re add them anyway. Hope this helps ! 🚀