Run off from coco ph3 !!!!

[Cisco]

Ok peeps ? I have a friend that's doing Coco and they ain't looking that good spotty , curled up a bit ! So he checked the run off and it's coming out at 3.0 !! Any ideas what would lower it so drastically ?

I don't have a clue about Coco but when I was doing my experiments I never checked my run off , only adjusted feed/water to 6.3-6.8

[Simon]

i think it would help to know what kind of ph-down, nutes, and water he uses. how often does he flush/get run off? i would say the ph down concentrates in the medium somehow. i am no coco expert tho. i read that lime (chalk?) can absorb carbondioxide and some acids and releases it by flushing it out. sorry bout my shitty english