So we have these mixxes we buy for our hydro setups...

B'cuzz A and B growth, A and B bloom, etc.

and people say not to grow different kinds of plants together at he same time in a SOG, because they use different nutes...

but all i do is mix part A and part B of b'cuzz for growth, and then A and B for bloom... REGARDLESS WHAT IM GROWING.

So i started wondering, if people cant grow different plants together at the same time, is there a way that they are testing their nutes to see what a specific chemical their plant is eating and not eating... that would cause them to use different nutes and suppliments for different plants?

Thanks!

the quick answer is, no. EC/PPM meter can't be specific, but there do exist specific equipment that can, I believe Fatman said professional farmers use them to automatically add back specific nutrients needed.

in regards to yoru other questions, there are simplified 'universal' formulas for veg and bloom. Lucas is a single formula for the entire life of a marijuana plant, for example. It is 5-10-9 NPK ratio.

there are some ways but i am guessing you dont have a laboratory, with a gas chromatograph or a mass spectrometer.

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It shouldn't be that hard to grow they do call it weed for a reason.

It cost about 25 cents for reagenst per eah nutrient tested. Typically only the major and minor nutrients are tested for but not the micro nutrients. Research laboratories at universities will actualy go beyond that degree of testing and actually test plant tissue (leaves) to see what chemicala are present. Therein the gas chromotography etc. Such testing is not done even by commercial greenhouses, but if done is done by laboratories at a very heavy cost.

The problem with even the standard, relatively cheap, testing is that the testing of nutriients in small resrvoirs is more expensive often that the cost of just replacing the nutrients by draining and refilling the reservoir. It takes commercial greenhosuses sized systems to make the costs worthwhile, especially when you consiser they pay about 50 cents per gallon for mixing up their nutrient concentrations. Figure just to test for Nitrogen, phosphorus, potassium, magnesium and calcium, you will need to buy reagents for a minimum of 100 tests on each and then buy the spectrophotometer or colorimeter to read the results. Figure the cheapest you can get a good used spectrophotomer for is asy $100 on ebay. Then add $125 for reagents and $25 for miscelaneous laboratory glass ware. So $250 minimum. Most cl olleges have cooperative extension centers that do testing for free or at cost, but I think they might not be ooperative about doing more than a few complete analysis withoutknowing why you wish all the tests. The most efficient method to do the testing is with ion specific electrodes. They are like expensive pH electrodes that only test for one specific ion/element. Sadly they are far from cheap at about $750 or more for each one. Plus you need a meter to plug them into.

To put it simply yes you can test very nearly excatly the amount of nutrients being used.

IMHO The reason to not plant different strains at the same time in the same system really has not much to do with different nutrient needs, as the needs are not that different amongst different strains. The main proplem is difeerent strains do not grow at the a same rates vertically, nor do they often reach a harvestable state at the same time. Really only clones from the same parent can be considered like enough to really be highly profitable when grown together. It is not very profitable to harvest in stages unless you can move the remaining plants under smaller numbers of lights etc. ie half as many plants in a system cost twice as much to grow unless you can shut half the system off.

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Ba da, ba da, Boom! It is as simple as that. Ba da, ba da, Boom!

Great advice guys! Thanks for the reply.

I guess i knew the stuff about different plants maturing faster than others, and i guess that is what people are talking about.

I simply have always used stations, and had a light for each stage, and once a plant starts running lean on nutes, its time to move them to the next station. Or if a plant is doing just fine on nutes, or the nutes are too much, keep it where its at and flush the plant with pure water from time to time.

As far as plants getting taller than others, move those to the outside of the table, and put the shorter ones in the middle of the table right below the light.

Thats been my technique.

If you are going to move the tall ones out to the edge you might as well cut the top half off and throw them away as you have just about eliminated any sufficient PAR to the tall plants tops. If your plants are in pots a better sollution would be to raise the short plants on pedestals to bring them up to the same height.. If your in somesomething like tubes then arrange your plants by height from one side to the other and tilt your reflector(s) or do the same arrangement and raise thetubes at one end and put the short plants on the raised end. Misters do not care if the tube is tilted. Taking plants that are growing well and cutting their light by putting them around the edges of the grow does not make economical sense. Your smaller plants in general are going to produce less so why improve their lighting and lessen the lighting to the plants that are growing better that would normally produce more buds? Such quagmires are why it is generally best when possible to grow like parent clones together rather than mixing it up. I use multiple smaller lights (250 watt water cooled) that can all be raised and lowered seperately and even with that versatility it does not pay off near as well mixing strains in the same aero grow.

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Ba da, ba da, Boom! It is as simple as that. Ba da, ba da, Boom!