As I succeeded in sending a first communication, here’s the information about my experiment. As I said, two weeks ago, I constructed a starter system that could allow me to get familiarized with all this first hand. I didn’t use the plans provided on the site, just browsed around, read a lot,thought a lot and observed. The funny thing is that, besides the need to buy hydroton, I didn’t spend one dime on my small and crude installation. Here is what I used so far :
. 1 2L soda bottle
.1 1L soda bottle
.1 1L Pedialite bottle (an oral electrolyte maintenance solution to prevent dehydration during diarrhea and which is also very effective to stop heartburns as well, by the way). The bottle is nicely square and I could open four windows in it, one on each side. But the plastic is not entirely transparent. Rather a smoky white. It’s the bottle at the bottom of the line.
. 1 tubing for slowdrip enteral feeding (my students are mentally and physically disabled and some can’t feed themselves by their mouths, so this kind of tubing is very abundant in our recycling bin and never comes in direct contact with the person, just with the feeding solution). See third photo. The product is american. Don’t know its cost, but it should be quite affordable.
. 1 4L ice cream container as a top reservoir (see the top shelve in the 2nd photo)
. 1 small rock to anchor the tubing to the bottom of the reservoir. See second photo.
. 1 metal container as bottom reservoir (it’s coated with a cooked layer, but I don’t remember how it’s called). See at the bottom of the system in the second photo.
. 3 plastic flower pots instead of net pots (the type you find in gardening centers when you buy baby perennials. The plastic of the cheapest ones is very thin and so flimsy you can compress them into the bottles without breaking them. Poking holes or cutting slits in the sides is also very easy.) I didn’t post any photo.
. Instead of hydroton, I thought of using my husband’s old glass marbles collection from childhood days, but since we want to give them to our grandson eventually, I refrained from that. Glass is inert, after all, and the marbles are the right size, but then I realized how hydroton is light-weighted, how it absorbs water and is full of small holes, so I don’t think marbles would be a good substitute after all. Besides, hydroton is quite cheap.
. For making a dark room, I simply used an old paper bag from a boutique. The exterior layer (the side with the store’s logo on it) was black, so I put that side inside to face the roots, showing only the regular brown paper layer.
. To suspend the whole thing, my husband gave me a roll of electric wiring that was gattering dust in the basement. It’s copper covered with black plastic and should be very sturdy. Each bottle was then secured with gardening metal wire covered with plastic as well.
My first experiment to make water run through the system was with the small 600mL feeding reservoir you can see on the third photo, put directly over the line of bottles (fine, since it comes with a nice handle to suspend it). But the water pressure doesn’t ensure a regular flow. This means that you have to ajust the flow with the clamp about every hour. And after three hours, the bottle was empty. That’s why I came up with the 4L (1 gallon) reservoir. The flow is much more regular, needing adjustment only every 18 to 24 hours. Plus, it lasted 72 hours before coming to a halt. Much better.
I’m currently trying other experiments to see how the system can be improved and I’ll come back to you with this.