Can I pre-mix nutes 14 days in advance?

[RandyL]

I'm going to be going on a 2 week vacation, and someone will be watering / nuting my plants for me. He doesn't know how to mix the nutes or PH them properly.

I use Fox Farms nutes for a soil grow. Grow Big, Big Bloom, and Tiger Bloom. Plus some molasses once a week, and other micronutrients in all waterings/ feedings.

I was planning to pre-mix and PH enough nutes to last 2 weeks, and just show him how, where, and when to water the plants.

I'm wondering if the nutes would "go bad" or have their PH change much while they are sitting, already mixed, for up to 2 weeks. Temperature in the room will vary from 70 to 95 degrees when I'm not there to put the A/C on during the daytimes.

I'll have to make one gallon now to test it, and set it aside, and measure its PH in a week or 2.

Anyone know anything about this?

 

[LighTer]

some nutes can react with what happens to be in the soil yes. but this chance you will have to take...it is slim.

Jorge Cervantes did it in his HT DVDs.

 

[RandyL]

I did all my nute pre-mixing on saturday 7/3. Last night 7/5 I called my assistant to see how things were going while I was on vacation. He said the molasses was smelling like it was fermenting or something, and stuff was floating on the surface. I hope this is nothing that will hurt the plants, I pre-mixed 10 gallons of fox farms nutes+molasses+beastie bloom for monday waterings / feedings, and 18 gallons of water+molasses+beastie bloom for wednesday and friday waterings!

I also left him 10 gallons of plain PH'd RO water as extra, just in case.

I don't know what the molasses would ferment with, other than the beastie bloom, nutes, or PH-up chemicals.

Can anyone tell me anything new on this?

 

[SnowBender]

Molasses is plant sugar, those sugars are whats fermenting. skip the molasses next time you leave. Is it well aerated?

 

[SteveHman]

Definitely the sugar (molasses) fermenting. As a homebrewer for more than 20 years believe me, it doesn't take much. Fermentation requires yeast, sugar, O2 and moisture (yeast also love minerals and it increases their growth potential). Unless you are using sterile water, and are filtering any air that it receives with HEPA (to remove stray yeast, which is everywhere), I would not add any sugars to a solution that will be left out for a few days. You can retard the growth of yeast with some additives from a brew supply store, but that will effect your pH as well.

And if all goes well and you can avoid the yeast infection, you still have to worry about bacteria getting into the solution. To echo an earlier post, I would forgo any sugars for pre-mixed nutes (although I am a novice grower, I am a very experienced brewer).

Cheers,
Steve

 

[RandyL]

This is a soil grow, in case I didn't mention it before. Not hydroponic.

I've got a 20 gallon tub filled with the 18 gallons of water/molasses/beastie bloom mix, and it is covered with the lid that came with the tub from Target.

The fertilizer with molasses in it, which is scheduled to be used on 7/12's nute day is in 1 gallon jugs with screw on lids.

Even if this concoction does ferment some, is it safe to use on the plants as late as next week? Or should it all be dumped and new stuff mixed up right away? I'm not there, and although my assistant could probably handle mixing new stuff, he doesn't access to the micro-nutes aside from the molasses. I hate to not have them going on the plants 20-something days into flower.

If this stuff could harm the plants, what would it do? It is creating alcohol in the mixture as it ferments?

 

[SteveHman]

RandyL,
Not sure if the alcohol will be a factor, but the pH may be lower due to fermentation. In brewing it's not uncommon to drop more than a point in pH value. Depending on the specific gravity and amount of fermentable sugars, pH may be a small concern. Although, if you have 18 gallons of water, it will take quite a lot of fermenatables to make a change (a few pounds of sugar). Also, if you have the fermenting nutes in sealed jugs, you are going to have a CO2 build up and that may also be bad, I would let the bottles "off-gas" before using them.

Again, my experience is coming from the fermentation side, I would check the pH prior to using the nutes though.

 

[mmclient]

The PH can migrate upward over time especially in the nutrient pre-mix. If your friend can check/adjust the PH (nice but not critical) and simply keep the nutrient mix stirred well this is enough. The comments regarding sugars already have been made.

 

[RandyL]

I got home from my vacation last night, and saw the carnage. Several plants appeared to have little or no damage, but the others were kind of toasted. The large fan leaves were shrunken and shriveled, curling in and down in most cases, in and up in the others.

The affected leaves can best be described as "crispy". Every part that isn't green is either yellow or brown. Squeeze them and they turn to powder. Some have some green in them, but the other 2/3 of those leaves are dead.

The little leaves coming directly out of the buds are ok for the most part.

What can I do? Continue a normal feeding / watering schedule and hope some leaves recover, or dead leaves are dead leaves and they should be trimmed off?

This will definitely affect my yield, and not in a good way. I was hoping for 2 ounces from each Skywalker plant, now I think I'll be lucky to get 1 ounce per plant.

The assistant didn't seem to be doing a very good job, there were signs of several spills in the grow room, and the water he was using had a 7.3 PH! He didn't even PH it right on the day he KNEW I was coming back on!

He also had the habit of putting his finger in the dirt to judge if the plants need water. I do not do that. I maintain a regimented, organized schedule. Monday, wednesday, and friday/saturday, they get food and/or water regardless of if the pots are dry or not. They are usually getting dry after 2 days.

 

[mmclient]

Sincere condolences...Does your 'friend' know what's at stake?

 

[RandyL]

Yes, but he has his own grow tent in his apartment, so my stuff coming out good and in high volume isn't the priority for him that it once was. I owe him an ounce for watching my stuff while I was gone, but beyond that he has no claim to anything in my room anymore.

At least the plants have survived, and the leaf damage is from the molasses fermenting, rather than something he directly did wrong.

I've got to research this molasses fermenting thing some more. Since the fertilizer day that screwed this all up consisted of Grow Big, Big Bloom, Tiger Bloom, Beastie Bloom, water, and molasses, I wonder if the molasses and its sugars reacted with things from the other nutes and make the problem worse.

It only took one bad feeding to cause the damage, I doubt it would have been worse if I had poured alcohol in the plants! Well, it might have been, but I don't want to find out!