NUTRIENT MIXING: Why does nutrient water need to sit? And also......

[bumblepuppy]

Hi growers. I am wondering why freshly mixed nute water should have to sit for 'some hours' (as the direction on my nutrient bottle states) before application. I have also read this advice from forum contributors. And a related question: Can anyone corroborate the advice given on GWE that it can be harmful to add a correcting drop or two of pH up or down after one has gone too far in the other direction? When I first understood the importance of correcting pH, I would add pH down, for example, find I'd gone too far in that direction so would then add another drop or two of pH up until I got the desired reading, not thinking that the additional corrections back and forth would be a problem.

[Beach_Town_Brit]

Hi bumblepuppy,

I think letting your nute mix sit is great, aerating it while it sits even better, but I don't really do either.
My compromise is make a double batch of nutes, feed one "fresh" and then the other one sits for 2-5 days till I use it.
To be honest I don't notice a marked difference between the plant's response to "fresh" nute mix waterings and watering using nute mix that has been sitting

I've done the Ph up and down thing at the same time before (small amounts <5ml of each) and it wasn't catastrophic but I avoid it these days. I know how much down my water takes nowadays so it never goes too low.

[Formernuke]

I think a large part of letting it sit is to allow the chlorine evaperate out if your water is high in chlorine. Other than that I'll be interested in what everyone else says.

[Beach_Town_Brit]

Good point Formernuke, I should note that my water does sit, I use a big brita filter.

One of the problems with relying on chlorine to evaporate is that a lot of water companies are switching to chloramine which is just as bad but doesn't evaporate.

[Mr.furley]

Howey yall
I let my 7 gal tap water sit, open, ph'ed for chlorine evaporation 24hr.
I mix room temp water to nute minutes before feeding.
I do premix for young vegging plant (they take less at a feeding so a big mix can feed twice, sit a bit and save time).
I don't ph down then up, if I feel unhappy with my mix I will add more tap water but like BTB said I know my water/ph down mix ratios.
ok then,That's my gig.

[Potted]

I understood the reason to let water stand for 24 hours was to let chlorine Evaporate. I won't ph water until all nutes are added and it sit for 24 just what I do .lol

[bumblepuppy]

Thanks guys for those comments. So, just to let the chlorine evaporate, eh? Nothing to do with some mysterious chemical interaction between nutrient components then?

[alltatup]

Hi puppy: I've never let my nute/water mix sit for hours; I'm using hydroponics, and I'm not about to leave the roots just sitting in an empty reservoir for that long. Plus, none of the nute brands I've used have recommended that procedure. What brand are you using?

As to the pH up/down question, I know that you shouldn't mix them directly together, but I have occasionally over shot the mark and I just add the opposite to bring into correct pH range. If the water is in the correct range, what's the problem?

[bumblepuppy]

I'm using Canna Coco in coir+perlite substrate. The actual bottle instruction says: "...stir well and let the mixture stand for some hours". No explanation is given for that advice.
I have never mixed the pH UP and DOWN together. That would seem to defeat the purpose. But, yes (alltatup), I have often had to adjust back when over corrected. I also wonder why that should be a problem (as suggested on the GWE pH tutorial).

[NA420]

I mix then feed, my water sits in BPA free plastic containers open 24 hrs. After i feed i refill the containers and put them back lid open. Wake up and repeat simple and easy! Peace!