Kratky Down Under

[Whwoz]

I have not been one for using Hydroponics, however seeing the results of @pepperhead212 and others on here I might give it a go. A number of things have lead to this point, the main ones being:

1. the greenhouse will need beds of some sort in it, which will be hard work and costly, especially if I get the mix wrong
and
2. The arrival of some different tubs here at work. These tubs arrive with food grade ingredients in them and will be thrown into waste after emptied if not claimed by someone for alternative use. In this case these sturdy tubs contained bagged Potassium Hydroxide pallets so do not need to be cleaned for this use.

IMG_20240718_195359_316.jpg

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These tubs are approximately 33 x33x 30 cm/13 x 13 x 12 inches (LxWxH) or 31.7lt/7 Imp gal/8.3 US gal in size and capacity.

I have net pots and was thinking that I could cut appropriate size holes in the lid and go from there. Smaller holes should do for lettuce, pak choy, mizuna etc, probably sneaking 4 per tub, with larger net pots for capsicums/peppers which are to be overwintered in the greenhouse.

Any thoughts or comments from those experienced with this type of setup would be welcome.

[PlainJane]

You’re on the right track from what I’ve seen here. I’m sure the hydro folks will weigh in.

[pepperhead212]

Are those tubs totally opaque? Seeing that they are white, I'm afraid that some light will be passing through, and if so, algae will grow.

I took some white buckets to make SIPs with years ago, and spray painted them with a green paint, and it pretty much bonded to the plastic, and that was for being outside, in the sun, and it has lasted for years.

As for the number of plants per pot, I have a deepwater setup with about 40% more volume and surface than that has, and have 6 holes in it, but once they get growing full sized, 4 basil, leaf lettuce, and mizuna have it pretty packed. Dwarf bok choys would probably be ok in the 4 for your tub, but those larger greens would probably be a little too much.

I never set up anything with the Kratky system, probably because I'm simply not comfortable leaving the water "stagnant" - always some sort of water circulation, an airstone, at the very least.

[Cole_Robbie]

Amen to the circulation idea. Kratky was doing research to try to help people in lesser developed countries grow food, people who often did not have electricity.

He was also in the cool mountains of Hawaii. High temperatures are your enemy. You will want to keep the reservoir water as cool as you can, so don't make it a dark color that gets direct sunlight. Some sort of mass around it like blocks or stones would help. If you did add a water pump, they make a little bit of heat, so insulation works against you.

You'll want the right size hole saw that matches the size of your net pots, or slightly smaller. Test a hole on a piece of scrap first. And use a drill with a side handle that lets you grip it with both hands. It is a safety feature so you don't sprain your wrist.

[rossomendblot]

This guy is somewhere near Brisbane I think, he has lots of hydroponic growing videos. Here's his Kratky tomatoes one:



I wrap my non-black containers in foil to keep the sunlight out. It doesn't get hot enough here for black containers to be a problem.

Four plants of lettuce, pak choi (smaller varieties), mizuna etc. would be fine for a container that size I think. Four plants per square foot is typical square foot gardening spacing for a lot of greens.

So far I have grown lettuce, coriander and basil with the Kratky method. It works great. My one semi-failure is Kratky cabbage, but that's mostly because the containers are outside and we've had so much rain for months that the nutrient solution has got really diluted.

[Ken4230]

Have a friend who runs a boat repair shop/tackle store who uses more than 300 blue barrels that he grows everything but corn in. Not sure if he's doing Kratsky but he fills the barrels with a fertilizer solution and plants things in the top. He is in the perfect spot with all the tourists heading to KY Dam Marina. He's got it figured out, selling fresh produce and some groceries. He has several barrel Strawberry planters. According to him, once he gets everything planted, it's almost no work other than harvesting. And his wife does that.

[svalli]

I grow everything in self watering containers in my greenhouse. I have not tried full hydroponics, because I am a bit of afraid of getting the nutrition solution stay correct.

All of my DIY containers are now with polypropylene rope wicks, which work great. I use two nesting containers with different depth, so that there is a water reservoir on the bottom of the deeper one and shallow one is filled with peat based potting mix.

self watering container.jpg

-Sari

[rossomendblot]

Those look great, Sari. My wicking containers are the Leon Sloan type:



Next year in the greenhouse I am thinking of making some DIY QuadGrow systems.

[svalli]

Those look great, Sari. My wicking containers are the Leon Sloan type:

Next year in the greenhouse I am thinking of making some DIY QuadGrow systems.

My outside containers are same type as on that video. I used pieces of plastic drainpipe cut into the height of the water level and put a landscaping fabric on top or it, so that it comes up to the sides and prevents the potting mix from falling into the water.

I know one lady who has that QuadGrow type system in her greenhouse. They had built long tubs lined with pool liner and covered that with waterproof plywood, which has holes for the wicks. I wish I had thought that before building my SWCs.

[rossomendblot]

Those look great, Sari. My wicking containers are the Leon Sloan type:

Next year in the greenhouse I am thinking of making some DIY QuadGrow systems.

My outside containers are same type as on that video. I used pieces of plastic drainpipe cut into the height of the water level and put a landscaping fabric on top or it, so that it comes up to the sides and prevents the potting mix from falling into the water.

I know one lady who has that QuadGrow type system in her greenhouse. They had built long tubs lined with pool liner and covered that with waterproof plywood, which has holes for the wicks. I wish I had thought that before building my SWCs.

It's a very versatile way to building wicking containers, I have used whatever I had lying around for the reservoirs: yoghurt pots, 1 litre plant pots, drinks cans, a 5 litre mayonnaise tub.

We bought my auntie set of QuadGrows for her birthday, and she's really happy with them so far. I am not happy with how my tomatoes are performing in the greenhouse soil for the second year in a row, which is why I am thinking of building something similar.

My plan is to buy some of these boxes - https://www.plasticboxshop.co.uk/boxes- ... -lid-p4078

The lid is wide enough that I can get two 10 L containers (ex-supermarket flower buckets) on top. I will make a hole in the bottom of the containers, and two holes on each box lid, then put some wicking cord through. Plus another hole for refilling the reservoir.

[pepperhead212]

Here are the sub irrigated planters (SIPs/wicking containers) I make, for outdoor planting. Shows how I make them using 4 gal in 5 gal, and 5 gal in 6 gal buckets, for individual planters, and a larger, square planter, and the 18 gal tubs. The watering is done with a dripline going into the chimney of each one, on a timer - it's amazing how fast those tomatoes suck up water! I have to set the timer to refill them every 12 hours, once the plants get established.
https://www.flickr.com/photos/91097628@ ... 900736848/

https://www.flickr.com/photos/91097628@ ... 810952858/

And here are the deepwater hydroponics I do inside, in the off season.
https://www.flickr.com/photos/91097628@ ... 578587486/

The first two photos show a 27 gal tub, that I put a plexiglass lid in, with all the holes cut, and spray painted white. It holds just under 23 gal, filled just under the lid, and I put that 8w powerhead with the sponge filter in it, plus an airstone (things I had around from all my fish tanks!). The last few photos show the 12 gal tub (just under 10 gal filled), with a floating Styrofoam lid. That's the one I referred to when I mentioned size, originally, as it gets overgrown with 4 larger type plants. You can see some of the lettuce, mizuna, and basil in the photos - things that get cut back frequently! Those things definitely aren't growing 4/sq ft! And the largest, most vigorous plant that I've grown indoors yet is the Russian red kale, which doesn't turn very red (much like the red lettuce, which just gets a blush, indoors), but once it is established, I have to cut it daily, and eventually, it gets too high, and I start another one a couple weeks before.

[Whwoz]

Hmmm, plenty for me to think about in the above comments thanks folks. I also have about 100 21lt buckets in the shed that could be used as either kratky units or combined into SIPs/wicking pots. Will keep my thoughts updated here and are not fussed if this thread gets taken over into a broader based Kratky thread