Flushing DWC. Any point to pH the water?
- Thread starter Blent
- Start date
That being said I Grow Hempy buckets not DWC
athomegrowing
Well-Known Member
The point of flushing in soil is to use the available nutrients in the soil, then allow the plant to cannabalize itself, removing "harsh" chlorophyll. With this knowledge, what do you think?
Logan Burke
Well-Known Member
From what I understand, because the plant is using already stored nutrients that have already been uptaken by the plants root system, it shouldn't have an impact on that. Now, if there are still ppm's in the water you want your plant to absorb, PH would then matter. Like in the week or two before flush, when you're running really low ppm's, but nevertheless still ppms. With that being said, I still try not to let my PH get too extreme one way or the other simply to avoid stressing the plant out.
Anothermeduser
Well-Known Member
Ph can still cause lock out on what's in the medium, proper ph will let the medium release what's there vs lock it up,
JSB99
Well-Known Member
Your plants need to have the pH level in range in order to transport nutrients throughout the plant. If you're just flushing, you're not going to be concerned about that. When the plant can't uptake nutes from the water, it starts to feed off of it's reserves (stored in the leaves).
So no, don't waste pH balancers on temporary water.
JSB99
Well-Known Member
I imagine it's to help remove excess salts from the roots. However, if you don't overfeed, this probably isn't an issue. I don't flush unless there's a problem.
Renfro
Well-Known Member
Salts don't build up on roots and any salts that the roots have already taken in can't be rinsed out.
The idea of a reduced feed or flush pre harvest, when growing in DWC, is just to prevent any further uptake of nutrients by the roots forcing the plant to use mobile nutrients that it already has in it's tissue. Nitrogen is the one that makes for harsh weed, dark green sparkler bud lol. So a feed that is very low in nitrogen but still has other nutrients is acceptable for finishing and will help the plant finish ripening properly. Potassium is key for terpene production and shouldn't be withheld IMO.
When I ran DWC I would just reduce the feeding of nitrogen and still feed the plants.
Everyone has their own opinions on flushing and I respect that.
JSB99
Well-Known Member
I'm with you, I feed up until about a week before harvest. I've never noticed harshness doing this. But I don't overfertilize, which probably would cause harshness.
Renfro
Well-Known Member
I like to use a feed that has a gradually tapering nitrogen content during flowering. I look for the lower fans to start yellowing as the plant is in later flower. This indicates that I am not providing too much nitrogen and the plant is using that mobile nutrient.
As I reduce the nitrogen I am adding phosphorous and potassium to maintain PPM. This will help make for better smelling and higher potency flower with an increase in yield. Magnesium and calcium should also be provided in adequate quantities. Not overfeeding and tapering PPM perhaps a little at the very end.
I have had people swear my weed is flushed and when I tell them it's not they can't believe it.
I am always playing with my nutrient mixes and trying new things. I am really liking the flexibility that I am finding with the jacks 3-2-1 that I am testing now against GH Flora 3 Part. With a few additives like monopotassium phosphate and potassium sulfate you can really set whatever NPK ratio you want as flowering progresses. Much more flexible than even a 3 part with calmag.
Well I digress... back to the original post, don't shock the plant with pure RO or a wacky pH. If using tap water and a pH thats close you will be good to go. If using RO then you should add 100 PPM of epsom salts to avoid shocking the roots. This is just my 2 cents. There are many theories about flushing and who is to say whats right except the grower.
As I reduce the nitrogen I am adding phosphorous and potassium to maintain PPM. This will help make for better smelling and higher potency flower with an increase in yield. Magnesium and calcium should also be provided in adequate quantities. Not overfeeding and tapering PPM perhaps a little at the very end.
I have had people swear my weed is flushed and when I tell them it's not they can't believe it.
I am always playing with my nutrient mixes and trying new things. I am really liking the flexibility that I am finding with the jacks 3-2-1 that I am testing now against GH Flora 3 Part. With a few additives like monopotassium phosphate and potassium sulfate you can really set whatever NPK ratio you want as flowering progresses. Much more flexible than even a 3 part with calmag.
Well I digress... back to the original post, don't shock the plant with pure RO or a wacky pH. If using tap water and a pH thats close you will be good to go. If using RO then you should add 100 PPM of epsom salts to avoid shocking the roots. This is just my 2 cents. There are many theories about flushing and who is to say whats right except the grower.
That is my understanding. I also remember reading a low ec solution actually does a better flush than 0 ec. Somebody did a long post years ago and it was all very convincing.
Logan Burke
Well-Known Member
Do you have any recommendations for how to add calmag during flower without adding any Nitrogen? All of the calmag products I see contain nitrogen, even if it isn't that much. The lowest nitrogen supplement I've found is CaliMagic at 1% nitrogen.
athomegrowing
Well-Known Member
Use Epsom salts. You probably don’t need calcium.
Logan Burke
Well-Known Member
Well, in my latest grow I had a very severe calcium deficit during late flower. Which isn't uncommon in DWC. Even after cutting out all nutrients but my base bloom nutrient, the problem only stopped when I slightly raised my ph from 5.8/5.9 to 6.2-6.4, and began adding CaliMagic at label strength. The problem is, being in late flower, not all strains can tolerate much extra nitrogen, so for situations like this I'd like to have a complete calcium and magnesium supplement that doesn't contain N. Does anyone have any suggestions in that regard?
athomegrowing
Well-Known Member
There’s no nitrogen calcium on amazon