Anyone not use a PK Booster near the end of flower? Your thoughts?

Hi OG, long time no speak, life getting out of control and all that.

I use a RDWC system and wondering if anyone does NOT use a PK Booster of any kind around 3 weeks prior to harvest? Products like PK 13/14 recommend to be added at this time.
I have used it a few times and found it interrupts the plant more than it helps. However, I am not very experienced in the area so just curious to hear others views.
I am thinking I will just stick back with my base nutrients and be done with it.

Good to be back!

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Always great when older members make a come back, as for pk boost. Nope just upped nutes depending on what she’s needing. I’m in soil to btw.

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Yeah they are better able to regulate themselves when going ONatural with soil. I do see the logic behind why the PK Boost my be needed at that time in Hydro. I just have not been successful with it.

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It’s better to drop a lot of the p at the end last couple of weeks , 1/2/6 : )
Pk I use from w3-7/8 ( so Rez 1/3/3-1/4/4 ) then w7/8 to finish 1/2/6 type feed : ) on say a 9/10 weeker
Pand k togeather make buds but at the end we want plant to finish so we drop a lot of the p in feed
Plant can’t make buds no more and is forced / pushed to finish
If you give p and k togeather at end then plant will foxtail more and take too long to finish

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I had some fast plants that that were growing out of control that needed phosphorous early to mid flower. I went to the local garden center and found some weird mag fertilizer thing for $6 that looked close to the ratio I wanted for flowers and it seemed to take care of the deficiency the leaves were showing. That was with flora trio when I ran out of part 3 bloom.

This grow I’m using megacrop 2 part and don’t intend to use anything else throughout the grow

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I use a high Potassium product like Jacks “Finish” or Deuce Deuce 0-0-22 at the end of flower as a bud hardener…

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When I used the canna line up with coco the directions for pk13/14 say only week 4 and 5 I believe but I found I had better results when I lowered the dose to 2ml per litre. I would start using it when there were buds forming and run it till the end. I’d always let them go a week extra and feed water only. So an 8 week strain would get low dose up to week 7 then drop the pk and just have the base for week 8 and have water for the extra week.

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Thanks for that ifish, I’ve been wondering about that too, my last run didnt want to finish with an npk of 132.

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Yes for sure. I still flush for the last 2 weeks. I am referring to PK Boost from 3rd last week to 2nd last week then flush for the last 2 weeks.
All I have found happens is that the change in the nutrients just interrupts the plants growth a little.

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I don’t flush tho I feed till the end : )

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ahhh k. Just drop the P. Makes sense. Ta for the tip.

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P at the beginning of flower, K at the end. PK boosters are usually just MKP and potassium sulfate. They could be used at either stage of flower, but unless your nutrient program is designed to use them, they’ll probably provide limited value… possibly even detrimental.

The supplement market is usually bullshit, because if you knew a better nutrient regiment, you would just design it that way from the start. If your nutrients need boosting, then maybe you should just use one that is better designed.

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Yeah, same end result as ifish mentioned i guess, reducing the P in effect. Thanks.

Yes, this is 100% my thoughts. If it would benefit it would be in there in the first place. I only see a use when you need a change to the nute ratios at some stage during the flower period. However, if the plant was not showing any deficiencies then it probably would not benefit. For this reason i have not used any additives until just recently. I looked at the PK Boost as a lot of people seem to do it. However, as mentioned previously I have not seen any benefit from it at all. If anything it interrupts the growth for a short while. The bottle is now finished and I will not be getting any more. In the past I have flip flopped between flushing for last 2 weeks and not flushing at all. Reducing just the P sounds like a better option.

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I use chempak 8 and pk or a combination of elixir high p and bumper tomato food plus’s added pk
At end of flower I just use the elixir tomato bumper
Cheap and easy to find in uk

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I think you are right. In my opinion, a 3 stage formula is good (veg, early, late flower). I think the PK boosters are intended as a poor attempt to make 1 stage formulas into at least 2 stage.

But the problem is that you need to have a purposeful plan for balancing your nutrients if you want to achieve a more optimal nutrient solution.

I think this is very possible. When you have too much K, it will reduce uptake of Ca and Mg. Also if your EC changes, then you fight osmotic pressures that could inhibit overall uptake.

There is no good way to add one thing like PK boosters generally across all the different nutrient formulations out there and produce optimal results.

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For sure. I do not change the EC either which means i need to drop the other nutes a little which probably makes it worse. I only used this booster the last few grows because it was a freebie. I wont be using any more. The plant will tell me when it needs something.

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I do constant EC based on Bruce Bugbee videos. 1.3 EC (20-10-20). For some plants I add a little more phosphoric acid in flower to increase P a little bit / but thats it.

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I never thought of it as a booster but I guess it is, but I’ve used Kool Bloom, since forever, in the last few weeks of flower @ 1/4 tsp per gallon of water, with a tablespoon of molasses in that 5 g’s of water.

I’ve begun to favor potassium nitrate over PK based formulas. Most fertilizer has plenty and I think most people underdo N and overdo P in general.

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