I grow on coco with Aptus nutrients and their "extreme" schedule and am having trouble figuring out why the run off PH goes as low as 4.2

@UnorthodoxDude: yes brand new Aquamaster, crossreferenced with an older one I had as well. @torresgrow I use Bionova buffered coco, also the run off ph is fine the first weeks of growing/flowering @Candog growing on coco is comparable to hydro so basically you feed constantly and excess runs off. My run off EC is an excellent 2.2 and I keep it within range with ph5.8 flush water every couple feeds But nutes definitely seem to stack up somewhere causing the ph to drop… if you google “ph drop coco run off” you’ll see that this is a very common issue…some say it’s normal and doesn’t matter as long as the water going in has the right PH…but I’m not too convinced and am after why this is happening:) THANKS GUYS FOR YOUR FEEDBACK AND HELP!!!

What are you using to test PH? Are you sure it's accurate/calibrated?

it's strange because the coconut will try to maintain a ph closer to 6, normally the peat moss that will tend to lower the ph, but 4 ph is too low, have you checked your coconut? did you wash it before use? try to wash it before planting with adjusted ph and see what happens, if it is coming out too low, you wash it a lot and then do the buffering with calmag

I see no diary connected on this so hard to say .but feeding twice a day sounds like to many nutes and lock out happening ,overwatering too ,but I don't know your set up so ...