After a number of years running the system you choose to run with, you won't be checking as much as you did at the start. I don't even need to pH and check my nutrient levels. I know what they are, as I've done it so many times. Having said that, I still check time to time for peace of mind
If it works it works.
Your explanation sounds logical to me - it makes sense. All I can say is that I've never had my plants experience any negative impact from not swapping out the nute water. But keep in mind, I mainly grow in soil - so my Kratky grow experience is limited... maybe 2-3 plants a year (I've certainly gone some years without any), almost always autoflower strains and probably only 25-30 such grows in my lifetime. So I'm far from an expert - it's just how I've always done it and for whatever reason, I've never had any issues with my plants - they've always been very healthy.
Yeah I don't ever PH or nute check either. I literally mix my nutes, drop the seedling in...check back in a month to see if I need to add more nute water. It's literally the most hands-off type of growing I do - although I have gotten into auto-watering/feeding for my soil plants recently to try to be a little more hands off on that as well.
Your less likely to see an issue with faster finishers like auto's. A 12week sativa not so much. I'm no expert either
Yup dialed inEven when I first started playing around with DWC in 2001 I wouldn't change out the nutes for all of veg. I'd drain and load them onto a new tub full of nutes geared for flowering when I flipped to 12/12 and that was about it. After a few grows didn't get around to changing nutes one run and everything seemed to go fine so I did a side-by-side grow with 2 tubs that had about 16 plants in each and did nute changes twice on one and none on the other and if anything the unchanged one did better. Pretty much equal in looks but the unchanged one yielded a little higher. As all the plants were from seed all things were not equal like they would be if I had used clones from the same mother. Same strain tho.
I basically applied my expanding knowledge of the plant's needs during it's various stages of growth to the nutrients I fed them so that they at least had adequate amounts of each when they needed it. When I first put clones into DWC I'll start them with equal amounts of all 3 nutes from my AN bottles at around 300ppm so a 1-1-1 ratio. Then as they drink that down a bit and start growing well I'll raise the ppm to around 500 using a 3-2-1 ratio of G,M,Bloom as they don't need all that much P and K in veg. About a week before I flip I'll boost the ppm using the 1-1-1 ratio again and add half a dose of Big Bud then the other half at the flip. By the end of stretch I'll have golf ball sized buds on top. Most people wait too long to apply extra P and K imo. Different in soil grows tho as you likely already have lots of those in there without adding more at the flip.
After the stretch I start feeding in the Lucas Formula style in a 0-1-2 ratio with Big Bud until the end of week 5 to lower N for a 8 - 9 week strain. Some of the sativas I would grow went 12 - 14 weeks so schedules were stretched out as was the stretch.
With the big tubs I would go 3 days before topping up with RO water then let if sit for an hour or more before checking pH and ppm. With rapidly growing plants the ppm would drop say 100ppm over 3 days and the pH would rise to around 6.3 so I'd add a small amount of nutes at the proper ratio to get it back to my target level and a few drops of conc sulfuric acid to drop the pH back to around 5.5 or lower then do the same in 3 days. With the advent of the pH Perfect tech I stopped checking pH at all. If you use those nutes don't mess with the pH. Pens don't read it properly and you'll mess up the technology by adjusting it. Trust the tech!
You for sure don't need to be changing nutes for most of veg. The plants aren't eating all that much and you're just tossing out perfectly good nutes then running out and buying more which is exactly what they want you to do.
Anybody wants a link to that side-by-side grow I did a journal on it at another forum. Been a while but should still be there.
Definitely not a good plan for nOObs but once you learn to read your plants fairly well is doable and your jugs of nutes last a lot longer. I grew my first buds in '78 so way past the nOOb stage.
I've only ever used RO or distilled water and know I couldn't get away with using tap water without changing more often. Tap water in town is close to 300ppm and pH 7.5 or higher with high sodium and alkalinity. My tap water is worse as it comes out of a dugout on my property and runs around 400+ppm and pH 8.4.
I'm a high school drop. Had a child young and started working to support a family. But I always enjoyed learning and spend my free time soaking up info and reading over the years. It drives my wife nuts and always has. My friends say I have an addiction to it. I believe anyone can learn and do anything if they want to. Have always been intrigued by the sciences of all kinds and think that would have been my go to had I stayed in school. Ask my wife what I'm doing when I retire and she will tell you "finishing high school and going to university" I guess I'm an odd bird.I've only ever used RO or distilled water and know I couldn't get away with using tap water without changing more often. Tap water in town is close to 300ppm and pH 7.5 or higher with high sodium and alkalinity. My tap water is worse as it comes out of a dugout on my property and runs around 400+ppm and pH 8.4.
I've always ran sterile in DWC too using peroxide for the first 10+ years then making a chiller out of a water cooler so found I didn't need the peroxide any more.
For sure you can have a lot of problems when you aren't experienced but that goes with any method really. I'm pretty certain that the majority of problems are related to poor water quality and always tell folks with deficiencies etc to contact their water supplier for a copy of their water analysis reports. All sorts of things in potable water that can build up in pots and throw everything off.
With hard water those minerals build up over time and adjusting pH to 6 or so won't make a bit of difference to the pH in the root zone when there is so much crap left in there from multiple waterings. Extra runoff or an occasional flush can help prevent buildup and save a lot of problems from happening. In hydro you should keep track of how much water is added back and change the nutes once you've added back as much as your system holds to prevent concentrating the minerals that are in your tap water.
Most micro-nutrient deficiencies are because of the pH being too high so I always recommend looking there first before tossing stuff in your pots. Generally makes things worse when you do that.
A big problem with soil or even soilless grows is getting a handle on the pH in the root zone. Testing initial runoff is meaningless as it's usually just a bit above what you are putting in at the top. The way commercial greenhouse growers do it is to water to the point of saturation first and discard any runoff. Then let them sit for at least 12 hours, add enough water to get some runoff and test that. That runoff should be caught in a clean container too so it's not influenced by anything left over from before. That will give a much truer picture of the pH in the pots. It can take hours before the pH stabilizes after a watering. With tap water in hydro it's quicker but a few hours before testing is best.
pH is a very complicated thing and I have a diploma in chemistry so most people have a lot harder time getting a grip on than I do. Easier to get it nailed down in hydro than in soil grows with all the other things in there.
Don't do it, school is overrated
I'm a lawyer and can tell you that there is nothing I know that you can't learn just reading books. The only time a degree is useful is if it's required by a government body to get a license to practice in a profession ... those who have them certainly aren't any smarter than anyone else. They may have been forced to read a bunch of books that you haven't read yet, but there's really no reason to pay outrageous tuition costs just to get a piece a paper that says you read a bunch of books 
.... but sure didn't like the price tag that came with it after I was finished!Yeah I never used distilled water or anything... just good old tap water. Maybe I've always just been lucky when it comes to hydro'n a little cannabis....I've only ever used RO or distilled water and know I couldn't get away with using tap water without changing more often. Tap water in town is close to 300ppm and pH 7.5 or higher with high sodium and alkalinity. My tap water is worse as it comes out of a dugout on my property and runs around 400+ppm and pH 8.4.
I've always ran sterile in DWC too using peroxide for the first 10+ years then making a chiller out of a water cooler so found I didn't need the peroxide any more.
For sure you can have a lot of problems when you aren't experienced but that goes with any method really. I'm pretty certain that the majority of problems are related to poor water quality and always tell folks with deficiencies etc to contact their water supplier for a copy of their water analysis reports. All sorts of things in potable water that can build up in pots and throw everything off.
With hard water those minerals build up over time and adjusting pH to 6 or so won't make a bit of difference to the pH in the root zone when there is so much crap left in there from multiple waterings. Extra runoff or an occasional flush can help prevent buildup and save a lot of problems from happening. In hydro you should keep track of how much water is added back and change the nutes once you've added back as much as your system holds to prevent concentrating the minerals that are in your tap water.
Most micro-nutrient deficiencies are because of the pH being too high so I always recommend looking there first before tossing stuff in your pots. Generally makes things worse when you do that.
A big problem with soil or even soilless grows is getting a handle on the pH in the root zone. Testing initial runoff is meaningless as it's usually just a bit above what you are putting in at the top. The way commercial greenhouse growers do it is to water to the point of saturation first and discard any runoff. Then let them sit for at least 12 hours, add enough water to get some runoff and test that. That runoff should be caught in a clean container too so it's not influenced by anything left over from before. That will give a much truer picture of the pH in the pots. It can take hours before the pH stabilizes after a watering. With tap water in hydro it's quicker but a few hours before testing is best.
pH is a very complicated thing and I have a diploma in chemistry so most people have a lot harder time getting a grip on than I do. Easier to get it nailed down in hydro than in soil grows with all the other things in there.
It's not so much about papers as it is about having an instructor who can answer your questions directly. Learning the theory's, processes, laws etc. is one thing but putting them into practice is another. I find once i start reading on one subject it opens up a lot more questions on others so it would be nice to have that source of information and expertise at my fingertips.Don't do it, school is overrated
Don't get me wrong, I loved school - lots of fun - spent my days socializing, drinking, and doing lots of drugs LOL...read some books somewhere in the mix of all that
I dropped out of high school too and to this day still don't have a high school diploma but in my early 30s went back to school as a mature student and spent 3 years at BCIT getting my environmental chem diploma. Never made any money at that so mainly drove trucks for a living especially once I made the mistake of moving up north in AB from the Fraser Valley in BC. Had two very young sons when I was in school and tehir mother left a couple years after I graduated so I became a single dad until they were old enough to head out on their own.
Fort Mac? I was born and raised in Alta. Sounds very similar to myself in regards to hobbies and did the single dad thing once my daughter hit 12 we split after 18 yrs. Married for the first time 3 yrs ago after an 8 yr go. Daughter just moved back home to go back to university. I am an avid fisherman and a lot of my family are in BC I'm always jealous of the Salmon fishing.I dropped out of high school too and to this day still don't have a high school diploma but in my early 30s went back to school as a mature student and spent 3 years at BCIT getting my environmental chem diploma. Never made any money at that so mainly drove trucks for a living especially once I made the mistake of moving up north in AB from the Fraser Valley in BC. Had two very young sons when I was in school and tehir mother left a couple years after I graduated so I became a single dad until they were old enough to head out on their own.
I've had all sorts of hobbies and pursuits over the decades but with most once I get good at it I seem to lose interest. Growing pot has lasted the longest and now I mainly grow for it's medicinal value. Getting into doing some serious breeding to develop some stable strains so that should keep me deeply involved until it's time to shuffle off this mortal coil.
Got a fishing license for the first time in about 4 years and will need to tie up a few flies that the pike and walleye might like so I have an excuse to get out and get a little exercise more often. Sure miss salmon fishing.