Kratkey fail

[HiPoha]

I have a tray filled with 25 gallons of water and decided to try the Kratky method of growing lettuce and assorted greens. I mixed in 60grams MasterBlend, 30grams calcinit, and 30grams MagSulfate. My results in growing anything has been very poor. Lettuce refuse to grow, bok choy are having a hard time , and so is everything else I put in there. What am I doing wrong? The grodan medium are sitting about 1/4 down in the water so the plants are getting what it needs. My previous nutrient solution did a lot better than this, maybe I should go back to that (CNS17).

[TeamTeke]

Have you tested the ph of your water? I have had excellent results with my greenhouse lettuce. Here is where I buy my nutrients(they do have a special lettuce and tomato formula) http://hydro-gardens.com/index.html

You can buy small amounts from them.

[beeman]

I have changed my methods of starting seeds for my Kratkey hydroponic set up.
I found that until the roots had gone down the plants took forever to get any size.
Now I start my lettuce seed it the rock wool cubes, this allows the roots to penetrate down, once they show below the cube I transfer them into the baskets, and I don't use those ball thingees.
I also now use Dutch Nutrient Solution A & B. You need such a small amount it's not expensive, but my plants really grow well in it.

[HiPoha]

The ph of the water could be a factor, since I haven't tested for that yet. I cleaned out the static tray and refilled with a solution of Jacks 10-30-20 and did the same for the other two pump circulated trays. They are in the second plantings right now and are doing okay. I gave up on lettuce because they grew bitter. All three trays are doing about the same.

[Cole_Robbie]

Are you using tap water? I think the treatment chemicals in it are locking out your nutrients. Often tap water contains high levels of calcium.

I've never been much of a fan of Kratkey. You would do a lot better with an aerated solution. A cheap aquarium air pump is a lot better than nothing. I think water pumps are even better. I use a mag-drive pump to pump into a manifold of pvc, with 1/8" holes drilled on the underside. The reservoir water goes up into the manifold and comes falling down through the holes. The more aerated your root zone is, the better the plant grows.

Another reason for you specifically to use aeration, if you're in Hawaii, I'm guessing it's warm there. Water has it's greatest capacity to hold dissolved oxygen at a very cool temperature, 57 F or so. As temperature rises, that oxygen-holding capacity is reduced exponentially.

Here are some pics of the last hydro mini-lettuce I grew:
http://i.imgur.com/G3eEmhe.jpg
http://i.imgur.com/HSjx5dy.jpg

I designed a system that works very well, but I still can't make it economically viable as a market grower. I was hoping I could produce spring crops faster with hydro, especially tomatoes, but my high tunnel plants in the ground came in ahead of the hydro greenhouse plants.

Next year I want to try a hydro-on-the-cheap experiment using rain gutters filled with whatever cheap media I can scavenge. I think any gravel would work. Run nute solution through it, cover the channels with aluminum foil to prevent algae, and I could grow some nice green beans.

[HiPoha]

Cole, I am using tap water and I do run an aerator through my noncirculating tray. The failure could be caused by the nutrients which could be lacking in the fertilizer in the Kratkey formula combined with the hot weather here. My new solution seems to be working fine right now. It could be improved by adding kelp meal or other organic nutrients which I'll try.

[Virtex]

Masterblend has worked great for me, in your first post you said you used 60g,30g,30g.
You should be using 10g MB per 5 gallons, 10g CaNO3 per 5 gallons, and 5g Epsom salt per 5 gallons. So, for 25 Gallons of water, it should be 50g MB,50g CaNO3, 25g ES.

Also, I noticed it looks like you are floating your rafts, not sure if they are or not but with the kratky method you don't float the Styrofoam it stays in a fixed location. I use this non floating method and include aeration for the double punch. If you have aeration on a floating raft it is not considered kratky just normal raft hydroponics. If you are floating then aeration is a must.

Your spacing seems kinda close, I space my lettuce 12 inches apart, so I can fit about 12 total plants in a 32 inch by 48 inch box.

Checking your PH is a must to have a success grow. Buy the liquid test drops they are very cheap to use. Without the proper PH your plants will starve. If you can collect rain water in a barrel I suggest using it over city water. I have used city water successfully just make sure you let it sit for 1 day for the chlorine to vapor off.

Organics in your hydroponics water just doesn't work and will cause you more problems than it is worth. I suggest you stick with Master Blend.

Please watch the following video this guy knows how to do it right:

https://www.youtube.com/watch?v=vYv9iu2NI3M

By the way Kratky lives in Hawaii and works at one of the universities, maybe you can visit his test location for some pointers, I hear he likes sharing his ideas with fellow Hawaiians.

Good Luck I wish you great success,

- Scott

PS here is a link to a few pics of last years lettuce and Pak Choi.

http://tomatoville.com/showpost.php?...36&postcount=5

[HiPoha]

Thanks for the helpful information Virtex. Mphgardener's videos were the reason for my trying the Kratkey method. The Masterblend fertilizer I purchased had the mixing formula that I followed which is different from yours. It shows 12grmMB, 6grmCalcinit, and 6grmMagSulf per 5 gallons. My growing platform is set atop cut plastic bottles and are not floating on the water. I have an aeration stone that turns on for 10 minutes every 2 hours. The spacing between plants are closer than recommended. I do need to check the ph of the water.
I didn't know Mr. Kratkey lived here. The University does have the Kratkey type of setup available on the web for anybody to replicate. Perhaps he was behind it.
Thanks again to everybody for your input. I'll try to correct my errors and try the Kratkey method again.

http://www.ctahr.hawaii.edu/oc/freepubs/pdf/sa-2.pdf

[Virtex]

The mixing instructions on the package are for tomatoes. MPHG has adjusted the instructions to work for leafy greens like lettuce and pak choi.

Since you live in Hawaii where it is hot all the time, make sure you buy heat tolerant lettuce. I have tried flame lettuce, adriana, simpsons black seed lettuce, red romaine and have had success in the summer. You might try some shade cloth if it gets over 90.

I think with a few tweaks you will do just fine.

Good luck,

- Scott

[solid7]

No offense to you, but how can you go into hydroponic growing without at least doing some baseline testing of things like PH and TDS?

[Cole_Robbie]

After a while doing it, you don't really need meters. You can just read the plants. It's a lot easier if you have good, consistent water to start with, like from a reverse osmosis filter. Fish tank water is really good, too.

I would run that air stone all the time.

[solid7]

Originally Posted by Cole_Robbie

After a while doing it, you don't really need meters. You can just read the plants.

Yeah, but the point is, you can't just dive in without having an understanding what you're starting with. The whole point of any type of hydroponics, is to be able to have 100% control over the growth inputs for the plant, and thus, optimize its growth. Otherwise, nature and/or conventional grow is easier.

I used the word "baseline" to illustrate the need to get some sort of a starting reference for this grow. That wasn't done, so it's very hard to troubleshoot.

[Cole_Robbie]

I've had so many failures when I thought I was in control, that I have given up on the idea of control. Read and react works better for me. Controlling the water I start with is most important for me. It seems like my water company changes their treatment chemicals all the time. Sometimes I get a strong chlorine smell and plants hate that water. Other times tap water works fine, which is what makes it so hard.

Both RO and fish tank water will tend to have a neutral ph. Nutrients lower that ph a little. If your water is pure, the TDS should be easy to estimate. And then if you just do complete reservoir changes instead of trying to add back what the plants used, you don't need to measure TDS.

Too low of TDS will make pale leaves, too high will make burnt leaves. Too low of PH will make leaves curl downward. Those are meters that never need calibrating. I have maimed plants before because I didn't realize my meter had gone out of calibration.

[solid7]

Originally Posted by Cole_Robbie

I've had so many failures when I thought I was in control, that I have given up on the idea of control. Read and react works better for me. Controlling the water I start with is most important for me. It seems like my water company changes their treatment chemicals all the time. Sometimes I get a strong chlorine smell and plants hate that water. Other times tap water works fine, which is what makes it so hard.

Both RO and fish tank water will tend to have a neutral ph. Nutrients lower that ph a little. If your water is pure, the TDS should be easy to estimate. And then if you just do complete reservoir changes instead of trying to add back what the plants used, you don't need to measure TDS.

Too low of TDS will make pale leaves, too high will make burnt leaves. Too low of PH will make leaves curl downward. Those are meters that never need calibrating. I have maimed plants before because I didn't realize my meter had gone out of calibration.

I gave up hydroponics, because I don't like the taste of hydroponically grown foods. Growth rate is phenomenal, but taste... Can't beat nature, unfortunately.

That being said... I understand that there are methods that are used that break from the scientific method. However, even when you know certain variables, there are others that you may not. Reservoirs get contaminated, diseases and pests move in, etc. I'm still of the opinion that when one grows in an unnatural way, it's best to be equipped for the job. Not that you need to constantly monitor - but you need to KNOW HOW. The aforementioned were examples of things that are evidenced by a shift in PH, aren't necessarily diagnosable, until you've been through it at least once.

Internet forums are littered with people seeking hydroponic growing advice, that have no idea what is in their water, or how it measures. I'm just pointing it out...