[Luches]

Originally Posted by GpsFrontier

Simple, the amount of nutrient solution required to do it. Most people don't have the experience to make there own nutrient concentrates thus they are not as cheep to us. For instance the broccoli plants I have growing in 4 5 gallon buckets only use a total of 6 gallons of solution. That is plenty to water the plants thoroughly and still have plenty in the reservoir to keep the pump from running dry. If the system was a flood and drain E/B it would take 20 to 25 gallons to grow the same plants. When you consider changing the nutrients every 1-2 weeks, over time that adds up to quite an expence for those of us that cant make there own nutrients.

Sorry, I don't agree here, because:

A. The setup I have designed and build is indeed run by a 180 L (aprox. 40 gal.) reservoir, but the actual growing beds (all 2) could be flooded with a total of 4-5 gallons of nutrients as well. Simply because the basalt and river gravel are actually using some 85% of the available volume (which is an estimate - the finer the gravel the more of the actual volume to fill, it will occupy already). In fact, the roots will fill up even more space (gaps) over time...

B. I did opt for a huge reservoir here to have more buffering for "long life" nutrient and stable PH. In fact one can run different strategies, either a smaller reservoir with frequent changes of nutrient, - or a larger reservoir with much longer autonomy and intervals of up to one month or 6 weeks. Depending on how much is toped up on a daily or 48h basis. Do you think that greenhouse setups with 1000, 2000 Liter or even bigger reservoirs, completely change it every 1-2 weeks ...? I seriously doubt it...

C. The fact that I am able to produce my own nutrients for a fraction of what you guys probably pay, doesn't push me to spill or spoil it, or even opt for systems that use more nutrients! Wrong anticipation, said the monkey and jumped off of the bear - I rather tend to save as much resources as I can, and thus am only running a different strategy. Besides, I can even tell how much it costs me: it's around 3.5-4.5 USD for 1200 Liter of ready solution, the price depends on P and K-content, as these components are notably more expensive compared to Nitrogen.

Originally Posted by GpsFrontier

An E/F system can be designed many different ways with as many growing containers as you wish and in many different shapes. I had strawberry's growing in 4 short flat containers and peppers growing in 10 small tall 2 litter bottles, both were E/F. I also have one built that uses one 10ft long 4in wide tubing. I can personally come up with many different configurations to do an E/F system, it would just depend on what it was I wanted to grow.

Did I say otherwise? Here I am just quoting what I wrote earlier...
I am not talking of rather fancy looking varieties of this application, but about the classical setup as described. All varieties mostly use a lot of tubing, multiple growing containers and other special features which aren't bringing any real advantage - at least as far as I can see or tell....

Originally Posted by GpsFrontier

Well that all depends on how you design your system and how large it is. I don't use any dripers, I make my own. Like with my broccoli plants a simple circle of tubing with holes poked in it works just fine, nothing expensive there. As far as the return line I guess it can get complicated with a large number of plants but not for me. Also any time spent figuring it out would save plenty of money in nutrients compared to flooding the same system.

What you said earlier to me about much cheaper nutrient costs, I could tell you here about dripers and other materials. Most people don't manufacture their dripers and haven't got the skills or even the tools to do whatever comes to their mind. Compared to (hopefully making my point perfectly clear this time) a single grow bed E/F system, - the return with drip and recycle, and with most other systems is ALWAYS a technical issue - that can't be denied.

And again, a well designed E/F system doesn't necessarily need a bigger amount of nutrient (or a bigger reservoir for instance). In case it's somewhat more, it can still be used for longer, before it needs to be replaced.

My personal (most certainly generally aplicable) conclusion: In this comparison I don't see any saving of nutrients - and the arguments I came up first seem still as valuable as before

I mean, I have nothing against controversial discussion of this kind - it's even interesting to some point. But then again, I sometimes have the impression that you don't really read what I am writing, but prefer anticipating things by yourself that I haven't said nor meant. In the other thread (heating nutrients) there was a missing part of the picture and that went on me. It's perfectly OK to have very own thoughts and understanding of things - but one has to at least fully read what was said earlier otherwise there is no understanding to expect. I am actually getting a bit impatient with the kind of "situation"... But never mind, just expressing my feelings early to prevent a greater misunderstanding.

PS: If you are interested in saving nutrients (for either reason cited in this context), you should truly learn more about nutritional needs of plants and how to feed the most adequate formula. Well, simply because the more appropriate a nutrient composition is, the longer it keeps usable and "fresh". The better the requirements of a specific plant are translated into a formula, the most you can obviously get of a "refill". A more or less inadequate (or standard) nutrient formula will obviously not be consumed to equal elemental parts and will obviously turn quicker into a even more inadequate mix.

The recommendation to change nutrients as frequently as one week to ten days is playing safe indeed, but it is not an economical strategy at all at the end (you bet!). People who change their nutrients that frequently should indeed keep their reservoirs as small as possible.