Thanks for the correction, though in my opinion the double power costs for slag seem to be the balancing factor there. Personally, I'd leave all the original recipes as-is (1 brick to 12 charcoal at 2.5MJ each), and eliminate the basic algae recipe entirely. As things are now, the basic algae recipe makes the others obsolete outside of a few edge cases.
Fair point. But for charcoal filtering, carbon for electronics, etc, all the charcoal costs are still the same as before, so it takes double the cellulose to keep up the same production rates.