If you disagree what is it you disagree with? my award winning plants? I don't think many people on this forum have growing issues, but holey smokes we all grow differently.
Also with out knowing everything about some ones grow as well as there initial water quality. Its hard to judge and when they tell you they are having excellent quality grows its hard to convince them there not?
But just take my system for instance (if you wish to save any money growing) The initial water is RO clean, i mean perfect! Then my system holds about 50 gallons of hydro. in one bucket i have a drip feed
pump (fairly big?), drain to waist or flush pump, as well as a cheapo wall mart dual air stone air pump.
Also you need to know if they use dehumidifiers and room temperatures plus is the air being exchanged or is aco2 being used by burner or tank
Aeration is a huge key to high quality hydro. must extend the life of a tank of
nutrients by 50% maybe? or more. then when you factor in that i dump 1 gallon of hydro ( which is pumped into my storage bucket for my out side plants) every day. this gives me in a 30 day period a 30 gallon flush on a 50 gallon system.
Now i top off my nutes at what ever rate they require. a daily testing in PPM with my pen meter indicates about 250 PPM using GH at its blooming formula on its bottle. running about 1500 to 1800ppm hydro base load.
So here is the deal. The plants will uptake what they need for the most part. If you are washing some hydro daily out and always adding the exact amount back in they have eaten there is a great chance that since they look perfect and taste terrific (cuke in hand as we speak eating, 18" long 1 3/4" around perfect flavor) that they are.
So its not that the tank is not being flushed its simply not being dumped all at one time. I have done the once a week dump and the two week dumps before with virtually no difference. when your computer is doing it is not tough to try and then verify.
Now we that said i have a second system of about the same size that has auto filler for water level and i drain it every few weeks i top it off randomly at best. these plants always look perfect some times I'll see a leaf color change and remember to run a ppm or flush.
Now how about this i have another system that i run almost all water in with almost no food and the plants plants produce miniature fruits with decent flavor. but every system has to have mixing or blending pumps and aeration and be sealed from light. Let light in and algae will grow and you will lose your control unless you have large tanks with lots of aeration.
Or i like this i just moved 9 vf 100 cherry tomatoes to my front yard from my main green room. with just garden hose water and some cheap terrible top soil i brought home in the dump truck there doing just fine. so to say a system wont work is odd at best. I'm always more interested in what didn't work. I mean what did you finally do to kill the pant off completely. Because that is the real tricky part. its easy to grow a plant but to kill it takes some one special.
By the way i am putting in a aquaponics system as we speak. just dug the hole for a 2000 gallon tank. hoping to go with lettuces and such with rainbow trout as they are native hear. Its just a few feet from the BBQ to keep it all really fresh. If any one is interested in bio filters used in hydro i have been looking into a system called the Skippy filter. just Google it. The new yard lake is 14' by 13' and about 3.5' deep. not to big but a lot of work i did by hand. with a 20 ft long stream that feeds into it. I'll post picts soon of it.