More Problems

Hi guys, not been on for a while due to our internet connection suddenly going down, BT came out after about 10 days & told us the hub we had was about 5 years out of date, installed a new model & up and running again, don't ya just love BT -not. Anyway more questions for you if that's ok. As some of you will know I've only been into this polytunnel lark since last June & I'm using this 1st year as a learning session, I've already lost my carrots,(too much manure), my courgettes rotted out & my pumpkins just wouldn't grow but up until now my Brassicas haven't been doing too badly, ok I had a big Caterpillar problem a few months back & more recently they were covered in Aphids but I seem to have sorted that, what's happening now is that the leaves are turning yellow & falling off, (lettuce/swedes/cauliflowers). I'm sure my watering regime is ok & every 2 weeks or so I give everything a liquid feed of seaweed so I don't know what I'm doing wrong. Another, & to me, a more worrying problem is with my Chilli plant, I've had about a dozen peppers off it with another 10 or so still growing & it's been fine, I spray with a mist regularly to keep the red spider mites off & they are probably doing better than anything in there except my beans. I went in the tunnel earlier on & since yesterday it's lost about 90% of it's leaves, they haven't fell off as there are none on the floor & I can't see anything on the remaining leaves so I'm baffled.
Any ideas.
Cheers
Lee:thumb: