Dial down nutes in final weeks of flowering or not?

[TieOneOn]

I've got some Girl Scout Cookies under a 600 watt led and want advice on the final stages of flowering. She has maybe 3-4 weeks left. I switched nutes midway due to lack of calcium. I was using foxfarm and was having a problem with ph levels creeping higher consistently, then I think she was receiving too much nitrogen which probably blocked the calcium intake. I corrected the problem by flushing her out for 3 days then switched back to technaflora nutes. This was my first grow using foxfarm and didn't like the ph issues, so I made the switch. I am doing a hydro grow.
I am curious as to the best method for adding nutes in the final weeks of flowering. Should I go high or low. Right now I dialed it down to around 450 ppm. It was at its highest around 1000ppm. I plan on flushing her out for 2 solid weeks before harvest.
Any advice on feeding in the last weeks of flowering would be helpful. Thanks.

 

[Bareback]

I have one plant in a dwc bucket using FF and I had the same problem but I changed my pH down from GH to diy sulfuric acid based and bam it was fixed instantly and so was my nute problems

 

[chemphlegm]

fox farm you say......

yes, dial down nutes towards the end of flowering period, just like the directions say on most I've read, it works out great, just like in nature, resources diminish, force plants to use up their stores and finish their fruiting.

 

[OldMedUser]

What kind of water are you using? High ppm tap water usually has a lot of carbonates in it that will keep pushing your pH up as the minerals in it build up in the system. Makes it hard if not impossible to get the right pH in the root zone. Builds up in hydro too leading to toxic salts buildup in the later weeks of flowering.

With hydro I remove half my nute water and replace with RO water to drop the ppm but keep it around 300 to the end. I tend to crop over a period of a couple weeks so they need a bit to eat so the smaller lower buds can fatten up and get ripe. A slow dry and good cure is the secret to smooth smoking, tasty buds.

 

[Dr. Who]

You don't have to dial back anything - You shouldn't be pounding the shit out of them anyway....
If your avoiding stupidly high P in late bloom,,,your good.

Veg is a set value. In bloom the N should tickle up as should the P&K for 2 weeks. Then the N tickle is removed, the P is raised and the K is also. For late bloom, you lower the P again and sharply raise the K....leave the N alone.

No flush, no stopping feeding....Proper slow dry and cure ....

I always offend someone who simply has to rely on self doubt from poor information or habit....
Just sharing....

 

[bryan oconner]

dr who . knows his shit . i am going to say lock out calcium . thats why they sell calmag . so when we push the p very high last 2 or 3 weeks to get every last so so out of them . no need to run straight water 2 entire weeks the most important stage this is when they get all there extra sugar coatings . last week of flower 5 days only i back off all nutrients and run straight water only reason i do this is because i pound the fuck out of them so hard there is a LOTTTTT of extra nutrients stored i want used up . i push the ppm 3 times as hard then suggested 1 week before i do straight water . this works for me not suggested for anybody . should throw in the 10k bulbs last week as well or t5 6500 or higher bulbs . best to follow your feeding tables or you could really hurt your plants if you dont know what your doing . i do not want to open a debate on flushing if you follow your feeding table should be able to follow dr whos suggestions .

 

[Bareback]

I agree @Dr who has helped me a lot but so have you @Brian O'Connor. And both of you make me laugh, just in completely different ways. I grew up with grumpy ass matter of fact old vets and I miss the hell out of em

 

[Aeroknow]

I learned from growing in recirculating setups that plants use less towards the end. A recirculating reservoir shows you what's going on.
I use what I learned and apply it to my drain to waste setups. The last two weeks i start lowering the EC.
Say I'm at 1.7EC for most of flowering. The last two weeks, i'll lower it. Say, 1.4ish for the second to last week, and then 1.0EC for that last week until chop.
It's what I do, and have done for many years. Doesn't mean it's the only way, but i feel pretty confident in it.

 

[Dr. Who]

I learned from growing in recirculating setups that plants use less towards the end. A recirculating reservoir shows you what's going on.
I use what I learned and apply it to my drain to waste setups. The last two weeks i start lowering the EC.
Say I'm at 1.7EC for most of flowering. The last two weeks, i'll lower it. Say, 1.4ish for the second to last week, and then 1.0EC for that last week until chop.
It's what I do, and have done for many years. Doesn't mean it's the only way, but i feel pretty confident in it.

This is very true! The plant requires less. It's also using different nutrients in differing amounts. N requirements are very low. P requirements have reduced back to about the amount used at the flip, and K has increased some. Having what you need available is the right choice!
The idea that you remove feeding in soil - "Because it's still in the soil" will short the needs over 2 weeks....

Your 35% drop in available nutrient is just about right. I might be supping the K a bit. Found that most hydro nutrients. Do a good job but, could allow for a bit more K and little less P those last 2 - 3 weeks. especially for high Sativa strains..

Once you see the "bulk" start...that would be the slow taper time....Abruptly stopping feeding is flat out counter productive....
most taper off to nothing in soils and that's not working either. If you stop feeding too much....The plant feeds off it's self. That does not improve flavor, burn or the cure....

Nice point Aero!

 

[jarvild]

Running DTW hydro I'm maxed at 1.2 ec (600ppm) on some strains but most of my feeds are 0.8-1.0 ec.

 

[TieOneOn]

Thanks for the great support. I am a true believer in a proper flush. However, I am open to trying new ideas. I've failed on a flush in the past and had sparkling bud when lit. So I'm a bit surprised when I hear of no flushing. Could it be the type of nutes I was using during the last weeks of flower? Too much N perhaps?
Anyway, I've upped my phosphate while keeping everything else the same, lower N and will lower again next week while keeping the P level where I have it now. Since raising it yesterday the plant responded and the buds are thriving.
So in the final week before flushing I will lower or eliminate almost everything and raise the potash sharply, then I will give it 5 days of flushing. However, after going through my nute products I don't have anything with just K that limits P. Any suggestions? I have a full complement of FF and Techna nutes, but the only blooming product without N and P&K is Beastie Bloomz. 50% P and 30% K. Should I just use that and eliminate all other nutes during the final week, eliminating usage of N? I usually up the Mg figuring it will add flavor. Am I wrong?
Correction: I did notice my Bushdoctor Bembe Sweet & Dandy solution is 1% P & 3% K , but it also contains 14% sucrose (cane sugar and beet sugar) plus 10% molasses. It sounds like something I should be using during the final weeks, but it contains very little P & K. I don't think it would be wise to use it alone, which still leaves me the problem of upping my K while lowering my P. Please advise.
I would like to add some pictures, but I don't like the idea of uploading pictures to one of my websites in order to use the link. How to go about that without leaving a trail to follow? Thanks.

 

[TieOneOn]

Thanks for the reply. I've posted again. Please reply.
On another note, I've added some fresh ph water, but kept the ppm at 650, by adding a shot of Beastie Bloomz and noticed this morning the leaves have curled a bit. This is usually due to high nutrients or heat stress correct? But since either should not be the case, (75 degrees with 45% humidity), could it be the P is too high? I'll wait to hear back before flushing it out and adding fresh nutes. I did add nutes on top of an older batch, while still adding more water. I usually don't do this but I wanted to feed her higher P & K.

 

[jarvild]

Excessive P is not necessary for good flower development. Only thing I do is remove 30 ppm of N and replace with 30 ppm of P. My last week of flower I'm running between 150-200 ppm.

 

[TieOneOn]

I'm flushing her out and adding a fresh batch of nutes. I have about 3 weeks to go before harvest. I'm going to lower N and raise the P&K a bit, nothing drastic. Thanks for the reply.