DWC Bi-monthly rez change question

[BudMasterzero]

I have a question for anyone who does DWC out there. I change my water every 2 weeks. So new nutes each week.

One thing I want to know is why do companies recommend you add more nutrients each week with a closed system like mine? Can anyone fill me in on what to do the 2nd week (of a 2 week water change schedule)?

Would it be good to add the nutrients suggested (I have Pure Blend Pro, but I don't like the thought of my ppm going through the roof). Or am I better off with the nutes I put in on the start of the 2 weeks.

I gotta say last time I really just added nutes the 1st week then used 1 mixed gallon to bring up my ppm over the week. Hell last time I got out of the plant what I wanted but I think there is something I am missing.

Any help would be appreciated. Currently starting my 2nd week of veg. (Damn you Cal deficient nutes!)

 

[FreezerBoy]

why do companies recommend you add more nutrients each week with a closed system like mine?

The more you use, the more you buy.

I do 1 plant in an 18 gal tub (12 g nutes) and do 1-2 res changes over a 20 week flower period. I wait to see signs of deficiency before flushing.

Nutes lack sufficient cal and mag because they expect you to add them through the use of tap water.

 

[gardenbug]

I do top off with fresh nutes whenever ppm drops. I try to do a res change every 2 weeks, but sometimes wait until they show problems from the solution being unbalanced, which could be a month. If you changed the res every week with new nutes it wouldn't hurt anything besides your wallet.

 

[BudMasterzero]

Hey Freezerboy I think you helped me out last time I was asking something! Thanks a bunch man. I am going to just let it ride then through the 2 week cycle and just bump ppm's up a touch with a premixed gallon. I also switched nutes from my last grow. I am using PureBlendPro now instead of Humboldt nutes. Basically I add 3 different nutes verse humboldts 5+. All I noticed for me was that I needed to folier feed with cal mag to right any mag cal issues.

To me it just drives me up a wall to see these companies suggesting on their bottles that you add too much nutrients.

gardenbug,
Yeah I don't see my ppm actually dropping, yet rising which I think is do to plant wastes.
I had a buddy who did weekly changes but he was running 2 5gal buckets compared to my 22 gallon tub.

 

[gardenbug]

gardenbug,
Yeah I don't see my ppm actually dropping, yet rising which I think is do to plant wastes.
I had a buddy who did weekly changes but he was running 2 5gal buckets compared to my 22 gallon tub.

If ppm is rising then they are drinking more water than nutes, so they are not underfed. Less water makes the nutrient concentration higher. If ppm is dropping quickly then they want more nutes.