Welcome John,

I my opinion, the passive systems are by far the most reliable. I have left wick sytems alone for up to three weeks without any problems. No experience with the raft system, but I suppose it must be equally reliable, and probably preferable for "leafy" veggies such as lettuce.

However, lets hear what others have to say.

Regards
Greystoke

Just my thoughts here. I might want to setup a drip irrigation system for the plants in soil. Learning about the PH and TDS(nutrient content) is not hard at all, it's just being gone for 2 weeks that might give a bit of a problem. Of course the plants would grow faster in a hydroponic system but the nutrient uptake is going to become greater as time goes by. If you were to fertilize the plants before you left and then had a small drip irrigation setup with a timer to go off every few days, that (in my opinion) would work for you too. You could take a 5 gallon bucket(with lid) and place a small submersible pump (150 gph) inside (at the bottom). Once you put the water in the bucket, let it sit for at least 24hrs so that the chlorine will evaporate. Cut a hole in the lid of the bucket big enough for a piece of tubing to go from the pump to your plant area. Really, instead of me trying to spell it out all for you, try looking and searching about drip irrigation online. It's all fairly simple. I say all this because, trying to watch the water parameters while being gone for 2 weeks is not so easy. Like I said before, if you just fertilize once before you leave and setup an automated drip system(that just consists of water from a bucket), it would all seem to be easier for now. Just my 2 cents.

While hydroponics is great fun I would not suggest it over soil gardening for situations where you are away alot. I have burned out pumps and had hole systems go dry when leaving them for much shorter periods of time.

Definitely drip irrigation is an option or check out the link for an even more elegant drip irrigation option.
http://www.rambridge.com/products/irrigat/tropf/tropfbu2.html
I have used the JR product that will water a plant from another container. I am interested in the main system but haven't invested in it yet.

Here is a link that might be useful: Tropf

Wow! That "Tropf Blumat" IS an elegant solution.

There are times that I can get very jealous over all those things that are available in the developed world. Did you know that Johannesburg is probably the ONLY place in ALL of Africa where the selection of goods is comparable to that of Europe and North America?

On the other hand, there is great satisfaction in achieving the same with the limited means available here.

Sorry about that particular link to the Tropf Blumat, on a closer look it is a Canadian site. I was searching for a us site that sells the stuff and I haven't been able to find one. I once did get a handfull of the Blumat JR but I think those are more appropriate for a houseplant or two that you can set a jug of water next to.
The Regular Tropf Blumat are more like a drip system with a built in moisture sensors.

Well, if you click on the "Distributors" link and scroll down, it will show stores by state here in the USA.

Thanks for the info. I thought about getting an ebb and flow system with an extra large resevoir, like 100 gallons. Im thinking that the extra large resevoir would be sufficient enough to get me through two weeks away. Does anyone have experiance with this and can anyone offer any advise on this,
Thank you

johntomato wrote:
Ebb & Flow systems . . Does anyone have experiance with this and can anyone offer any advise on this,

Can't say if 100gallon is enough. All depends on the number of plants.
I suggest that you build your system and try it out thoroughly. You will soon find out what might go wrong. My problems are invariably related to the timers and clogging.
Try and keep it simple. The more complicated, the more likely it will let you down.
Check your TDS before you leave and adjust with concentrated nutrient. Check pH and adjust.

Good luck

tclynx wrote:
The Regular Tropf Blumat are more like a drip system with a built in moisture sensors.

I think the tips of these units are loaded with "swelling powder" similar to the crystals that you described to me.
The swelling operates a valve, then cuts off the water supply.
Ingenious!

Something to definitely keep in mind for a system that will be left alone for a while, a float valve that will add water to the system when it drop below a certain level. I've burned out pumps when the resivuar ran dry before I got the foat valve. Is this system going to be indoors or out? Danger of indoors is that a leak could turn out to be major issue (especially if there is a float valve involved. Think flood, not leak.) Outdoors you have the varying weather to contend with which makes estimation of what the plants will need difficult.

Good luck

tclynx wrote:
. . a float valve that will add water to the system when it drop below a certain level. . .

The trouble with a float valve in an ebb & flow system is that the valve must NOT operate during the flooding sequence. This can be accomplished by adding a solenoid valve in-line operated by a timer. You can then program a window (say: at night) whereby the systems gets topped-up.

But by now you have: two timers, a float valve, a solenoid valve, a mains water pressure reducer and a pump in the system, and - to be entirely honest - that is not exactly a recipe for reliability. Here in Africa one has to contend with under-, over- and no voltage of the electric power grid. I have an under-voltage protection unit on my circuit board, but I can do little about over-voltage. Not at all helpful! I go through a toaster, a coffee percolator and a couple of timers every year.
So, if its reliability you need - at least here in Africa - stick to passive systems.