Hydroponic nutrient level vs lighting power

I am using a 150W HPS mini sunburst HPS and the GH flora gro series in a hydro DWC setup.
With such a small power lamp, do I need to adjust down the nutrient level of the flora nutrient chart suggested by Hydrofarm ?
Will I waste nutrients if I follow that chart ?
The plants are doing all fine, no burn, great yields, just wondering if I am wasting stuff...
Thanks !

as long as your plant thrive, dont change anything.

that's another way to say you don't know shit ??? hahaha
don't reply if you don't know the answer and of course, it was not my intention to change anything, but to UNDERSTAND

Light will always be your limiting factor; light is the food for plants, not the nutrients which are merely the building blocks for metabolic processes. Increase your light if you can before pushing nutes harder.

And yes those GH feed charts are way off and you are right to ignore this and under feed!

Also vital is your fertigation rate, which I think of as the regularity of supplied nutrients at a certain concentration. This is important when deciding nutrient strength and hopefully demonstrates zero logic in amping up feed in line with light power. The inverse is likely true.

For example in veg I run coco on an automated drip recirculation program, feeding 3 x 1min every day at an EC of 1.8 max. If I were to increase this to 5 or 6 x 1min per day as I do in flower (with more powerful lights) then I typically drop the EC by 10-20% to reduce the concentration of salts with more waterings.

This avoids salt buildup as the medium is effectively being refreshed more regularly, and is more economical on nute usage.

pppp1500 said:

that's another way to say you don't know shit ??? hahaha
don't reply if you don't know the answer and of course, it was not my intention to change anything, but to UNDERSTAND

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wow dont expect much help with that attitude.

weedemart, don't worry i don't need you to reply...
and if you read, i am not asking for help but information.

However ruwtz is much more interesting.
I like his explanations, and what I ask is : if light is the limiting factor, how low can the nute level be without missing anything ?
Curiously, i've never seen any guide mentioning such relation between the nutrient concentration and lighting power in any guide. Never seen a table with suggested ppm levels vs watt (HPS lamp).

In fact, I am using dwc systems, thus root exposition to nutes is not a parameter, same for nute solution volume (or level)
I won't change the lighting, I am more than happy with the yields.

Having more frequent water changes with lower nute concentrations would help... but if you calculate properly, this would lead to a bigger waste !
A more clever idea would be to replace more frequently only a part of the reservoir with fresh solution instead of full water changes. Bah more efforts that's not what i am searching for !

I am curious about what you mean regarding the gh chart... how much lower levels are you using it ?
I'll try using 30% less nute and if it impacts the yields

pppp1500 said:

if light is the limiting factor, how low can the nute level be without missing anything ?

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Bottled nutrient lines - 3 part, A&B etc - are complete so you won't miss anything; the quantity you add in solution determines the concentration of available nutes. So many factors can determine this amount: grow method, planting medium, genetics, sterile or using amendments/beneficials etc.

pppp1500 said:

Curiously, i've never seen any guide mentioning such relation between the nutrient concentration and lighting power in any guide. Never seen a table with suggested ppm levels vs watt (HPS lamp).

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And thats my point, I don't believe there is any such correlation, except to say that you should be feeding in line with growth. If you're dropping 80,000+ lumens on your plants then chances are they are metabolizing incredibly quickly and you can feed accordingly, not forgetting fertigation rates as I explained upthread.

You could just as easily find NFT peeps feeding at 1.2EC start to finish, or someone with dry salts with identical lights pushing 2.6EC or more. So many other variables.

pppp1500 said:

A more clever idea would be to replace more frequently only a part of the reservoir with fresh solution instead of full water changes.

Click to expand...

This might not always be so clever in a recirc system as you have no way of measuring depletion of one mineral over another. So your res of 1.5EC has unknown levels of NPK and all the rest. Better is to run it down and change out frequently.

pppp1500 said:

I am curious about what you mean regarding the gh chart... how much lower levels are you using it? I'll try using 30% less nute and if it impacts the yields

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I don't use GH but plenty of info out there by people who do. You might consider Lucas formula if economizing time, effort and cost is your thing.

Again, feed to match plant growth phases, and get away from the idea that nutes is in any way in charge of your yield.