Quick question, do you use veg nutes until they show sex/flowers, then switch to flower nutes? I just found out about this method and threw 11 seeds in paper towels (check my sig). Im super excited and want to make sure I'm prepared/do it correctly for the best results.
Here you go, if you don't want to read what is below, then I'll say it now. you can use veg nutes through flower and still get good results.
Here is a nice tip for you new growers that pack your plants full of P (Phosphorus) When you start to see buds!!
The High P Myth - The Overuse of Phosphorous in Hydroponics
It has been shown that phosphorous (P) is possibly overused by many hydroponic growers. Tissue tests conducted in 2003 by Advanced Nutrients through BC Research Inc on numerous cannabis strains demonstrated that cannabis plants require far less P than is present in many hydroponic nutrient formulations and additives. The tissue tests also demonstrated that N, Ca and K are required at far higher levels than P and P, while required at somewhat higher levels in bloom than grow (as is shown in numerous studies), is required at far lower levels than would be expected. Another surprising outcome was N requirements in flower (re cannabis) were higher than previously believed. These findings contradicted conventional beliefs among hydro industry professionals and others that high levels of phosphorous are required to achieve optimal flowerset in hydroponic settings (among other things). [SUP]1[/SUP]
In recent trials conducted by several US based medical growers, it was shown that optimal P levels in DTW/RTW coco were at approximately 60ppm during mid to late bloom. This figure was shown to be similar in soils – with as low as 40ppm of P in soil producing extremely good results.
While these trials lacked what would be considered standard scientific qualitative checks and measures (eg. no control was used to measure outcomes with higher and lower ranges of P in side-by-side trials) what became apparent over several months and several crop cycles was, 1) low P in solution (approx 20-25ppm) helped to reduce stretch and shorten internode gaps (setting up better plant structure) during the first weeks of the 12/12 flower cycle, 2) no yield benefits were obtained above 60ppm P and 3) resin production was optimal at 60ppm of P and seemed unaffected at even lower levels in both soil and coco (<40ppm). [SUP]2[/SUP]
Similar findings with tomato crops grown in soilless culture support these findings.
According to Spensley et al.,[SUP]3[/SUP] a typical nutrient solution for tomato production has the following composition: N: 150-200 ppm, P: 30- 40 ppm, K: 200-300 ppm, Mg: 40-50 ppm, Ca: 150-200 ppm and Fe: 5 ppm. Moreover, Winsor and Massey noticed that yield of tomato fruit was reduced significantly by low potassium concentration. [SUP]4[/SUP]
What these findings suggests is that many manufacturers of hydroponic nutrients and additives have their NPK profiles wrong and that an optimized PK additive should contain higher levels of K to P than is typically found in the vast majority of Potash products.
