I have decided to try an experiment for my second grow – which will also be my first time doing hydro. I know, probably a crazy idea, but I like to tinker around with new things and this sounds like fun and it wont kill me if all the plants die 
Im going to run three different types of hydro, at the same time, in the same small tent, on the same rez - using only a single air pump.
If anyone is curious, this all started with this thread:
So, why three kinds of hydro at the same time? I’ve been reading a ton of hydro threads, and it occurred to me that the only real difference between the different types of hydro is the ratio of air to water at the root level.
At one end of the spectrum are things like DWC, water farms, hempy buckets, etc., where at least a portion of the roots are completely under water 100% time. The % that is above/below the water varies, but at least some portion is fully submerged 100% of the time.
Then there are things like EBB/flow which change things up on a cycle – lots of water then no water, then lots of water. I think they fall more or less in the middle.
At the other end are NFT systems and hi-pressure aeroponics, fog-ponics, etc., in which the roots are never completely submerged. They are mostly in the air with just a constant thin film of water or micro droplets.
Also at this end is a relatively unknown (to pot growers) new type of hydro called Membrane Meniscus. It is basically just an extreme type of NFT with even less water contact at the root level than a typical NFT or aeroponics setup.
Each type has its proponents and detractors, and success, and failure stories. People have been successful with every type of hydro – but which is “best”? I have yet to see anyone who has done side by side grows where the only variable was the type of hydro.
Im bored, I like to fiddle around with new (to me) tech, I have a bunch of seeds from a single plant, and it occurred to me I could actually fit three different types of hydro into my small tent with very little effort, and very little cost – so why not?
I don’t really expect to see a huge difference between the three types Im going to do, but I wont know until I try it. If there is any significant difference, I have my money on the Membrane Meniscus. It has the potential to provide the highest air to water ratio of the three types Im going to try.
Im going to be running three 5 gal totes side by side in my 7 sq ft tent. All will be growing the same seeds, started in the same medium (perlite), under the same LED lights, using the same water with the same nutes from the same rez.
So the only variable will be the ratio of water/air the roots get based on the type of hydro running in each tote.
Tote 1 will be ebb/flow (highest ratio of water to air) – with three twists.
First, the ebb/flow cycle will be a constant loop. It will run 24 hr a day, 7 days a week. Most ebb/flow setups I have seen go longer between fills and many only fill/drain during the day. So this setup will be closer to a DWC as far as water/air ratio than most ebb/floe setups.
Second - It will be regulated by an automatic siphon (that costs less than $2 to DIY) inside the tote – no timers or submersible pumps in the rez. There will only be a single aquarium air pump that drives an airlift pump to deliver the water. It will take aprox 30-40 minutes to fill the tote. Once the water level gets hi enough, the siphon will automatically trip and the tote will empty in aprox 2-3 minutes. The cycle will immediately start over and repeat as long as the airpump is running.
The third twist is the media I’ll be using. Im going to use a mix of lava rock and small pieces of scrap plastic pipe for the main media. The plastic pipe pieces are to save on weight, and to create voids in the media to make extra room for more root growth. Im hoping to get a larger root mass that way. At the top of the tote will be a small container of perlite to start the seedling. It will probably be a 2” long piece of 2” PVC pipe filled with perlite, just sitting on top of the lava rock mix. The reason for the perlite is so all the seeds start in the same way in each tote. Each one will have perlite for the seeds to start in.
Tote #2 will be the NFT tote – again with a twist. Im going to be running the water film through a thin fabric mat on the bottom of the tote. The roots will grow into that mat as the plants grow. This tote will also have a PVC pipe, drilled with lots of holes and filled with perlite, extending up from the mat to the top of the tote. There is a video in that other thread I linked to with details on this. This tote will be the middle ground as far as the ratio of air to water exposure for the roots.
Tote #3 will be Membrane Meniscus – the absolute minimum water/maximum air in the root zone. Again, the theory and details are in that other thread.
All three totes will be insulated from the grow tent as much as possible to help reduce rez water temps. All three will be getting their water from the same single air pump driving the same single airlift water pump. Most of the water will go into the ebb/flow tote with smaller portions divided off to the other two totes with the Membrane Meniscus tote needing the least amount of water. That same air pump will also aerate the rez with some DIY air “stones”.
Im about 2 to three weeks from harvest on my soil grow. I’ll start the hydro project as soon as possible after that. I will be building out the totes and rez as much as possible over the next several days and I’ll post pics as I go along.
There is actually a second thing I want to test with this grow. Im curious to see which method gives the best harvest, but Im also wanting to see if any of them gives a significantly larger root mass. Its been suggested that larger roots make for larger harvests. Id like to see if there is any truth to that.
As always – questions, comments, suggestions, corrections, etc., are welcome!
