Beginner's fertiliser for hydroponics

I saw this interesting video on off-grid hydroponics where the guy talks about fertiliser. Having watched the vid, I got a basic grasp on fertiliser suitable for lettuce and such.

So I got the basic notion of NPK and he suggests something like 20-18-38.

I'm not sure what to buy for that, so did some looking around and found some stuff on ebay, first thing I clicked on and it was worm castings which had a profile of 2-0-4... which is way low compared to the above number.

So I'm wondering if that's unusual, or most fertilisers are that low or what. And where should I buy some. I'd like organic is the thing - and water soluble (for the hydroponics).

A lot to ask maybe!

 

Im sure there is no such thing as organic hydroponics ,do you live in a hard or soft water area?

 

surely minerals are just minerals though, what is it that's not organic about regular fertiliser anyway?

I'm not sure about the water, how do I test?

 

20-18-38 is the same as 10-9-19 - but you need twice as much of the second to get the same effect as the first

Hydroponics is a whole different ball of chalk to growing in soil. Soil already contains a whole load of nutrients, and in particular "trace elements", whereas none of that exists in hydroponics so you have to provide them all ... moreover the soil acts as a buffer, storing elements for when the plant needs it, in hydroponics the plant can completely strip a particular nutrient from the solution; the normal approach in amateur hydroponic setups is to chuck the nutrient away (weekly, say) and replace it with fresh, thus ensuring that everything the plant needs is provided; in bigger setups they have a chemistry lab and test the solution and adjust the concentrate accordingly. Hydroponics is a long way away from most people's idea of organic ...

With soil based crops you can nurture the soil - by making compost and adding that to the soil - which then leads to healthier crops; long time since I read about it, and thinking may have changed, but back then there was a line of thought that good compost making put back goodness that improved the plant's immune system - rather like humans that have a good, balanced, diet I suppose.

 

Thanks for the info.

Well, the only thing is, I keep seeing videos of people comparing their hydroponics to their soil crops and there's a huge difference in favour of the hydroponics (and aquaponics). Been looking at the Krakty method whereby you don't even need aeration via pumps.

 

Hydro is not soil,soil has micro organisms that are symbiant with roots of plants,the micros feed off decaying root and clean the root back to fresh root which then feeds on the excrement of the microbes.. where as,dissolved minerals only prooves the plant will choose any port in a storm ..could be costly
Do you get lime scale on your kettle etc is a way of knowing
P.S

 

I just did a check on a website that said I live in a hard water area.

 

In that case(hard water) youl prob need a deutch 2 part formula called canna aqua made by canna but you will need to google nutrient stength & which PH lettuce thrive at
P.S you will need a ph pen and ec metre.... i find tesco easier x

 

I think of hydroponics as lacking flavour - too much water in the fruit. But, in fairness, the only hydroponics fruit & veg I eat comes from the supermarkets and their suppliers grow varieties that don't bruise easily, and mature all-at-once to make harvesting easier, rather than varieties that have outstanding taste (and it is the varieties with great taste that us amateurs choose to grow ).

I worked on a commercial hydroponics nursery in my early 20's, and I was involved in the science side of horticulture quite a bit, and nothing would induce me to grow my own home-veg that way. Having said that I have plenty of land, so no need for hydroponics, but to my mind there are a lot of downsides:

Lot of kit, and thus cost, to get started
Cost of the chemical fertilizers - much more, and specialist ones, needed for hydroponics compare to growing in soil.
Risk of a powercut meaning the plants have no nutrient solution for hours and are either seriously stressed or die
My perception that there is less taste (may be unfounded if high-flavour varieties are grown)
I think its "growing in chemicals" rather than natural

 

That's good food for thought (no pun intended). I hadn't thought of it that way. I just saw people comparing their big, fluffy hydro veg to their weedy, half dead soil grown veg and figured it was a no brainer.

And would you say getting organic fertiliser for soil is different/easier than water?

 

OK,playing devils advocate here: it may well be easier to grow "big fuffy vegetables" in hydro than soil, for a novice. It is almost certainly easier to grow Cannabis that way!

Depends on your definition of Organic. Organic growers would not use a granular "Growmore" fertiliser. To my mind its a simple inorganic chemical compound, so I don't have a problem with it. The things that bother me are the complex organic chemical (I'm using "organic" in its chemistry sense, not its "green environmentally friendly" sense).

Take Chicken Manure. Most people would think of that as Organic/Green. But what about if it came from chickens in a battery farm? that were fed plenty of Antibiotics in their diet? How would you know whether the chicken manure pellets in your garden centre came from battery farms, or not? (The ones in my garden centre are labelled "Organic" but no reference to the Soil Association Accreditation, so its probably meaningless). A few years ago JWK bought some bags of manure from his garden centre which was labelled Organic. It contained residue of a herbicide used by farmers on pastures from which hay was made and fed to cows the following winter, and the manure from the cows was processed and bagged and sold in the garden centre - AND labelled "organic". It killed all his crops (and the crops of lots and lots of gardeners on allotments across the country). The herbicide it contained was strictly licensed such that this should not have happened, but the farmers / contractors either didn't read the instructions, didn't care, or A told B and B didn't realise he also had to tell C ...

If you make your own compost, and use that on your soil, and don't use any insecticides or other "complex" chemicals on your food crops then you will know that the provenance of the food that you grow to eat is as good as it can be. That's what I do - although I would use a chemical (an insecticide say) if I was faced with the total loss of a crop. I would prefer to know that I had used X, and waiting for at least the correct number of days before harvesting, rather than buy in the supermarket and have no idea what had been used on it, and whether the farmer, perhaps in a foreign country with more lax pesticide rules, had obeyed the rules to the letter.

 

A lot of the tasteless hydro veg that comes from supermarkets is grown using the bare minimum of nutrients needed, probably similar to growing veg in poor soil. If they get a nutrient rich diet they taste great.If we get a summer this year i`ll send you some toms for a taste test
The only real difference between soil and hydroponic nutrients is the hydroponic nutrient uses nitrate (NO3) in place of urea and chelated micro nutrients (Fe is the main one). Chelates are fairly common in soil nutrients too, check the label for EDTA

Dont buy hydroponic nutrients from "those" kind of shops, they`ll charge you a fortune.
Looking at some of the positives, i find blight affects my soil toms at least a month earlier than the ones in hydro. The soil toms are usually dead and gone well before the hydro stops producing.
Here`s a comparison of soil and hydro toms that came from the same cuttings and were planted at the same time.


This guy grow toms, cukes, strawberries and courgettes using glass for media and chempak nutrients.
http://www.the-poly-croft.co.uk/Hydroponics.htm

 

Doesn't surprise me to hear that one of the main "drivers" of commercial hydroponics is cost. Having said that it is quite remarkable how dramatically the price of food, as a proportion of average income, has fallen during my lifetime. We got suckered in to a one-stop-weekly-shop at the local supermarket in the late 80's (which our lifestyle became tight-for-time) ... then when Tesco starting doing online shopping I moved to using that, and we re-factored the time we spent in the supermarket to buying things at old fashions butcher's and deli's - over that intervening period I had completely forgotten the fantastic flavour of food from my youth when my Mother fresh-cooked everything as there were no ready-meals in those days, and am glad to have that back again; grow-our-own veg (and Pork) is a big part of that for us, to grow for flavour rather than yield.

So I'd like to say a big thank you to Sir Tim Berners Lee

 

Dry nutrients are much better value for money. You wont find them in those kind of hydroponic shops because theres less profit compared to selling it with the water and plastic bottles. The bulk of the postage cost will be in the water weight