would sodium carbonate be a safe alternative to sodium hydroxide?

Thank you.

Sodium Carbonate is not basic enough to extract DMT.

Sodium Hydroxide works great. As does Potassium Hydroxide (Advanced Nutrients pH UP)

sodium hydroxide isnt dangerous so long as you take obvious safety precaution and if your that scared some goggles and what could possibly happen then? ruin your clothes if you spilt it all over yourself haha

You could use the Q21 tek, it uses Calcium hydroxide which is just pickling lime.