Kratky Hydroponic help wanted.

[P4nth3r]

Hi all,

I've been growing tomatoes, lettuce, herbs, micro greens and peppers in soil for a long time and it works great but I want to move into hydroponics to get better results.

I grew some seeds in rockwool til about 2 inches of green and 2-3 inches of roots then transplanted them into 5 gallon buckets with a water/feed mix, no bubbler. I left enough space to let th3 plants 'breathe'.

My problem is the roots are going mental but there's no new growth on top. I literally have 10" roots with 3" of top growth.

By comparison, the seedlings introduced to soil are almost 2 feet tall now despite being planted into their respective mediums at identical times. Both sets of plants share the same lighting but the soil variety are fed slow release soil food.

I don't know what I'm doing wrong.

Thanks in advance.

[imafan26]

It is probably your water feed mix. Are you using Master blend for Tomatoes? It is better if you have aeration. A bubbler is better to keep the water moving and the mosquitoes down. Tomatoes usually benefit from using a high growth mix in the beginning and a high phos mix when fruiting.
Tomatoes have different nutrient requirements at different stages of growth.
Below are links to Kratky experiment results and methods on how he set up his system. It includes the set up for tomatoes. He used a masterblend of nutrients that was designed for the system. You can get masterblend for tomatoes on amazon as well.

https://www.greenhouse.cornell.edu/crops ... ecipes.pdf
https://www.ctahr.hawaii.edu/hawaii/dow ... matoes.pdf
https://www.ctahr.hawaii.edu/hawaii/dow ... method.pdf
https://kratkyhydroponics.com/

[Gary350]

I have a friend that works in a green house in Chicago where they grow seeds in a cotton balls poked in a small hole in a PVC plastic pipe with real sunlight to make plants grow. I tried this one summer 30 years ago, I pumped water from a mud hole in the garden through a PVC pipe and back to the mud hole it work good for the small plants in nice weather and real sunlight. It will get complicates with grow lights, chemist to keep water right, green house & large plants.

[imafan26]

It is easier with a short crop with relatively the same nutrient needs throughout the growth cycle. Heavy feeders require certain nutrients in different quantities depending on their stage of growth.

[P4nth3r]

Thanks for the replies
.
I did the following as an experiment.

I made 2 pots around 5 gallon each, 3 seedlings in each, one with just water, one with water plus standard tomato feed (4.0 nitrogen, 2.0 phosphorus, 6.0 potassium, minimal magnesium.) They all grew at the same rate and stopped at 3 inches tall. The same seedlings in soil are over 2 feet.

It must be the feed? I've seen people grow huge plants without a bubbler so it can't be that.

I'm doing the method perfectly except the proper feed but again, they should grow in just water to a certain extent (when I root cuttings in a jar they go mad with nothing but water).

I will get some proper hydro feed and sow some more seedlings and get back to you guys

[applestar]

I don’t know anything about hydroponics, but I was wondering how the roots are getting air/oxygen if there is no bubbler. Also,without aeration, don’t you end up with overgrowths of anaerobic microbes in the reservoir?

In this method, is there an air gap beteeen the reservoir and the basket/container with the whatever media you are using, like with SIP’s? Also, is there air vents to the air gap?

[imafan26]

In a Kratky or raft system setup there is an air space between the crown of the plant and the roots. The crown of the plant is not in contact with the water. Air roots grow in the air space and water roots grow in the liquid. The water roots must be constantly wet or they will die. Healthy roots are white. Dying roots are brown. As the level of water drops in the system for short plants like lettuce, there will be more roots exposed to air and less in the nutrient solution.

When you water root a plant, the nutrients are coming from stored nutrients within the plant. Eventually, those nutrients will run out if it is not supplemented.

Aeration has been shown to enhance growth by increasing oxygenation, but it is also better to keep water moving to keep mosquitoes from breeding in the tank.

When we grew tomatoes and cucumbers in a dutch bucket system. The water came from aquaponic tanks. It still needed to be tested and adjusted daily to maintain pH around 6 and ec measured. Iron was added to the water since lettuce and other plants needed it and it could not be provided by the fish. We use cinder in the dutch buckets (15 gallon nursery pots) The aquaponic water was pumped from the fish tanks to the dutch buckets via pvc pipes, Water flows into the pots from the top and a lined tray collected the water and returned it to the tank. We also fed the plants with organic fertilizer. 2 parts fish meal and one part bone meal. In hydro rail and aeroponic towers a controller constantly measured and delivered a nutrient system to the plants. We did have rafts but those were converted to grow beds.