Mixing a batch of nutrient water

[Fourpey]

I plan on growing drain to waste and am wondering if I can mix batches of 5 gallons of water and use that for a couple of days instead of mixing feeds each day.

I have this big igloo 5 gallon water dispenser that has a spigot and need to know if its ok to use that because it would be very convenient.

If so, would checking the pH be necessary every time or do the nutrients stabilize pH once mixed in? I'll be using GH Flora Series and CalMag.

 

[hoobastank_enthusiast]

If you're going through 5 gallons in a couple days then that should be fine. In coco, the concern with reservoir temperature is less about dissolved oxygen and more about the potential for any foreign microbe growth. But going through it that quickly, in a container that is sealed from light, you probably wouldn't have any problems. You'd just want to keep an eye on it to make sure nothing is ever growing and clean it out regularly.
I do the same thing on a smaller scale, I have 1 gallon jugs and I'll mix up two or three every time I make nutrients. One gets plugged into my autofeeder (they last 2-3 days each, depending on where the plant is) and the others get stashed in the refrigerator for later.
The pH should be relatively stable given that you're going through it so quickly and it's shielded from light, but the longer you let it sit at room temperature the more that would be a concern. But again, with the time scale of a couple days, I doubt you'd run into any problems. Assuming your pH meter doesn't explode it never hurts to check, so do so if it makes you more comfortable.

 

[Fourpey]

If you're going through 5 gallons in a couple days then that should be fine. In coco, the concern with reservoir temperature is less about dissolved oxygen and more about the potential for any foreign microbe growth. But going through it that quickly, in a container that is sealed from light, you probably wouldn't have any problems. You'd just want to keep an eye on it to make sure nothing is ever growing and clean it out regularly.
I do the same thing on a smaller scale, I have 1 gallon jugs and I'll mix up two or three every time I make nutrients. One gets plugged into my autofeeder (they last 2-3 days each, depending on where the plant is) and the others get stashed in the refrigerator for later.
The pH should be relatively stable given that you're going through it so quickly and it's shielded from light, but the longer you let it sit at room temperature the more that would be a concern. But again, with the time scale of a couple days, I doubt you'd run into any problems. Assuming your pH meter doesn't explode it never hurts to check, so do so if it makes you more comfortable.

Thanks for the reply! Yeah I'll only be growing 2 plants in 3 gallon fabric bags and estimated around 1/2 a gallon to 1 gallon of water per plant each day. So if everythings goes accordingly I should be mixing a new batch every 2-3 days. Does 1/2 a gallon until runoff twice a day for 1 plant make sense in a 3 gallon bag?

 

[hoobastank_enthusiast]

Thanks for the reply! Yeah I'll only be growing 2 plants in 3 gallon fabric bags and estimated around 1/2 a gallon to 1 gallon of water per plant each day. So if everythings goes accordingly I should be mixing a new batch every 2-3 days. Does 1/2 a gallon until runoff twice a day for 1 plant make sense in a 3 gallon bag?

I am also in 3 gallon pots with the timeframes I described so your estimation may be a little bit on the high side but it will depend on your environmentals. It's hard to hurt coco with overwatering but you may not appreciate the amount of waste generated when doing so.
You can still take a day doing a full gallon or whatever and then at the end of the day just see how much runoff that produced. My guess is it's going to be in the ballpark of 25% runoff (waste) where we really only need about 10% to get the salts out appropriately.

 

[Fourpey]

I am also in 3 gallon pots with the timeframes I described so your estimation may be a little bit on the high side but it will depend on your environmentals. It's hard to hurt coco with overwatering but you may not appreciate the amount of waste generated when doing so.
You can still take a day doing a full gallon or whatever and then at the end of the day just see how much runoff that produced. My guess is it's going to be in the ballpark of 25% runoff (waste) where we really only need about 10% to get the salts out appropriately.

Alright, I'll keep an eye on that. Maybe I'll start with 1/2 gallon/plant feed a day in veg, and move to 2 feeds approaching flowering when they seem to need more.

 

[hoobastank_enthusiast]

Alright, I'll keep an eye on that. Maybe I'll start with 1/2 gallon/plant feed a day in veg, and move to 2 feeds approaching flowering when they seem to need more.

You just want to make sure to keep the media saturated and get a little bit of run-off each day. In terms of volume you can always start with more and dial it back, that's the safer play. It becomes apparent pretty quickly when you're just passing water straight through saturated media. In terms of concentration, I also use GH (6-part + Si) and I think their feeding charts are accurate. To that point, you can use a stronger concentration if you're only watering once or twice per day. There's a whole other conversation about watering 1-2 times per day versus 6/8/10+ times a day but honestly you can get good results either way.

 

[Fourpey]

You just want to make sure to keep the media saturated and get a little bit of run-off each day. In terms of volume you can always start with more and dial it back, that's the safer play. It becomes apparent pretty quickly when you're just passing water straight through saturated media. In terms of concentration, I also use GH (6-part + Si) and I think their feeding charts are accurate. To that point, you can use a stronger concentration if you're only watering once or twice per day. There's a whole other conversation about watering 1-2 times per day versus 6/8/10+ times a day but honestly you can get good results either way.

Cool thanks! I was planning on using the grow weed easy feed chart, any thoughts?

 

[hoobastank_enthusiast]

Cool thanks! I was planning on using the grow weed easy feed chart, any thoughts?

So my problem with custom feed charts (GWE, C4C, etc.) is that generally speaking, no one can give you an objective answer as to why the inputs have changed. You'll get anecdotal or pseudo-scientific reasons ("we don't need that much _____ right now", "That's what ______ uses and they're great") but there is typically no scientific rigor apparent in any of them. I've also spent time fucking around with custom charts from various sources, tweaking them and trying to make them my own, and I've never had as good results as when I just stuck to the guidance GH has published. For those two reasons I stick to the manufacturer's recommendations. That's not to say that somewhere/somehow you can probably do it better; I just haven't really got there yet.

 

[hoobastank_enthusiast]

If you really want to fuck around with your own ratios, I'll kick you this little nugget, it's the EC concentration of your nutrients per mL per gallon distilled H20, you can use these values to quickly calculate the estimated EC of whatever custom formula you're dialing up.

 

[Fourpey]

If you really want to fuck around with your own ratios, I'll kick you this little nugget, it's the EC concentration of your nutrients per mL per gallon distilled H20, you can use these values to quickly calculate the estimated EC of whatever custom formula you're dialing up.
View attachment 2167752

I'm not familiar with all the terminology yet and don't know what EC is. I'm trying to follow some kind of easy guideline at first to get a feel for it. I only have a pH tester and tds tester for now.

So my problem with custom feed charts (GWE, C4C, etc.) is that generally speaking, no one can give you an objective answer as to why the inputs have changed. You'll get anecdotal or pseudo-scientific reasons ("we don't need that much _____ right now", "That's what ______ uses and they're great") but there is typically no scientific rigor apparent in any of them. I've also spent time fucking around with custom charts from various sources, tweaking them and trying to make them my own, and I've never had as good results as when I just stuck to the guidance GH has published. For those two reasons I stick to the manufacturer's recommendations. That's not to say that somewhere/somehow you can probably do it better; I just haven't really got there yet.

Alright! I'll try to follow this and if my results are not good I'll try whats on the bottle

 

[hoobastank_enthusiast]

I'm not familiar with all the terminology yet and don't know what EC is. I'm trying to follow some kind of easy guideline at first to get a feel for it. I only have a pH tester and tds tester for now.

Alright! I'll try to follow this and if my results are not good I'll try whats on the bottle

https://ezgrogarden.com/hydroponics/ec-vs-tds

EC is electrical conductivity and is the objective measurement that all derived measurement scales (e.g. TDS and PPM) actually come from; it's a more ideal way to measure solution concentration than derived scales like TDS because it is purely a measurement rather than a value calculated on assumption.

https://generalhydroponics.com/wp-content/uploads/assets/GH_FloraSeries_FeedCharts_USD_01_WeeklyBasic.pdf