Does bleaching dreads hurt them in any way?

Can I thicken my dreads by simply doing nothing?

Hey, i've had my dreadlocks for 2 months i am african american my hair is extreamly curly and thick . It seems every time i get my hair retwisted it crawls back aloose? The only part what doesnt come loose are the tips i used the 2 strand method . Any tips or advice about what to expect in the next month?? Help im starting to think this isnt gonna work.