Totti, what temp were you at? I'm assuming the numbers in parentheses is the temp in Celsius. Back when I started with Ischia, I tried 1.3% and then kept increasing it, even trying up to 2.5% which resulted in too many large bubbles. I've found 2% Ischia to be just right and for the last year or so that's what I've gone with for a 48 hour rise at 65F in my wine fridge. The activity level of my starter varies a bit, but I never have underfermented dough. On day 2 of fermentation, in the morning, I'll check the rise on the dough balls. If they still have a way to go, I'll leave the temp at 65F. If the dough looks close to being fully fermented, I'll dial the temp down to 60F or so.