Imo you should add the ALA now. You could go with with 12 and a half mg ALA+25 mg DMSA next round, just in case you get a strong reaction to ALA, although the strong reactions to ALA tend to occur much more often when ALA is used without DMSA. One thing that helps when chelating with ALA+ DMSA is to do two or three doses at the end of the round with just DMSA. This helps decrease the day after side effects. If you do okay with this, then you could go to 25 mg ALA+ 25 mg DMSA in a few rounds. Andy Cutler recommends using a ratio of ALA to DMSA of between 1 to 2 and 2 to 1. Then the next increase after that could be to 25 mg DMSA + 50 mg ALA.

So far I have been staying between the 1 to 2 and 2 to 1 ratios, and am now at 100 mg ALA + 50 mg DMSA. I am tempted to go to 3 to 1 since DMSA is so much more expensive than ALA(10 times the price!), although I am afraid I might get more side effects going higher than 2 to 1. Perhaps I might just stay at this dosage a few more rounds and see how it goes.