see. Ok here's a q for ec, I rest tap and sometimes don't get to it for 6 to 7 days. How much will this affect the O2 levels and would it be beneficial to run an air stone for a few hours prior to watering? I'm sure the answers are a lot, and yes but your the man so whacha think?MG def. starts in the lowers, veins remain green while the rest starts to yellow from the edges inward, leaf turns yellow, curls up and dies. leaf edges will feal dry/crispy. as it advances moves to middle and upper half and the new growth shoots will change from pale green to white. stems/petioles will turn purple as well. it's a common deficiency and one of the easiest to resolve quickly (thankfully). the plant uses a lot to support healthy leaf production and structure, especially @ wk5-6 as they explode in growth
chef u r the shitchef .... U already know the answer a lot and yes. Really shouldn't make much of a difference with soil plants, as the action of watering pulls fresh air down into the rootmass. With hydro, it is a little more important. H2o temperature affects o2 absorbtion, colder water temps hold more oxygen (this is one reason why a chiller is good for hydro)
t ... With ro water, you don't need to let it sit. The whole reason for letting it sit is to let the chlorine evaporate off. Ro removes all chlorine/chloromine.
Another trick to neutralize chloramine is to use ascorbic acid *vitamin c*. Adds some micros too. The half time of reaction between ascorbic acid and chloramine is about 4 min. 1gram to 40gals roughly. Otherwise, it takes @ 24hrs of sitting out to breakdown (high intensity light can help too)