Friday, May 29, 2009

Friday, May 29 - The last post

This photograph was taken May 24th. Later that day I transplanted the tomato plants into large pots. I was going to continue this experiment, but it immediately became clear that I do not have the resources to boil enough water in a microwave to keep these plants properly nourished. Tomato plants, as they get larger (and, of course, they get very large) require a lot of nutrients, and a lot of water.

The plants in the photograph are the largest from each grouping - microwave-boiled water, tap water, kettle-boiled water. They have all been sprouted from seed. To this point I can see no evidence that treating water in a microwave oven has had any negative effect on these plants. This is also a conclusion we would have to reach after viewing the previous experiments, detailed below.


ammaka said...

Hi Robert,

I am thinking about doing this sort of experiment, so I am curious about the specific types of materials used for it -- for example, what kind of container did you use for boiling water in the microwave? What type of material coats the inside of your water kettle? What temperature was the water heated to in the microwave, and what temperature was it at when you poured it into the soil? Any other tips would be great too! Thanks!


Jennifer said...

I recently did a similar experiment using wheat grass seeds. I had about a 50% lower germination rate for the microwaved water. (I didn't do a kettle water test because I didn't have a 3rd planter.) So, I had 2 batches of seeds from the same package.. one watered with tap water and the other with microwaved and then cooled tap water. I didn't just microwave the water once and then use it until it ran out, I remicrowaved it and cooled it each day in case there was an effect that wore off after being microwaved. My question is did you just microwave the water once and have it sitting for days or did you microwave it each day?

Robert W. Harwood said...

Apologies for being so late in posting and responding to your queries: my wife an I moved from Ontario to Saskatchewan and I neglected to update my email address with the blog provider.

I heated the water in the microwave using large ceramic cups. The kettle I used is one I have been using for a couple of decades - it is a plastic Filterline kettle, manufactured by Philips. Once the water had boiled, I stored it in sealed glass containers (of the same size for each type of water), and did not use it until it had reached room temperature.

Because I was dealing with relatively small amounts of water, I was generally boiling the water every second or third day.

Interesting that your seedlings germinated at different rates - as you might see from my two experiments, I found no difference in germination success. The tomato seeds were from the same package.

Anonymous said...

Very interested in your blog & experiments. It's sad tho that there's been no update since May 2009.

Robert W. Harwood said...

You're right, it has been a long time. I don't anticipate returning to this, though, at least not anytime soon. My life suffered quite an upheaval last year and my wife and I needed to change many things. I am, however, maintaining another blog at but it has nothing to do with the experiments here.

Thanks for your comment!

loves2spin said...

Thank you for doing this!

Anna said...

Thank you for doing this project - it's great to be able to see what is and isn't scientifically supported out there. I appreciate your effort.

Robert W. Harwood said...

Thanks, Anna. I appreciate your comment.
Apologies about taking so long to post a reply - I just found out I needed to update my contact info after moving.

Anonymous said...

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Robert W. Harwood said...

Thanks for the note. I have found no problem with the images in the blog, but did note that several of the links were outdated and I have deleted those.

Anonymous said...

Hello, I want to subscribe for this website to obtain most up-to-date updates,
thus where can i do it please help.

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Robert W. Harwood said...

Thanks. But I have not posted to this site for quite a while - since 2009. There will be no more updates.