I'm an idiot

My cabbages and brussels have been really struggling to put on any growth, to the point of looking really poorly. At first I thought it may be bad compost but other plants seem fine so it had to be something else. Then I hit on what I think it must be……bleach! I put a dash of it in my water butts to sterilise the water and even though it’s very dilute I noticed the water in the watering-can still smelt quite strongly of bleach (In fact I may have put more than just a 'dash' of it in). I reckon the brassicas obviously don’t react to being showered in the stuff. You live and learn. I’ve sown some more and will have to remember to water them from another drum without added bleach!