Hey everyone, after reading about the membrane meniscus hydroponic system on Larry3215's thread: https://www.rollitup.org/t/three-types-of-hydro-in-a-small-tent-on-one-airpump.960095/ I did a little digging, got in touch with the inventor Andrew Parker and also read his book on the system. On paper it seemed like the next step in hydroponic systems as it claimed to be a recirculating system where the PH and EC dont change throughout the grow, the roots get the maximum amount of dissolved oxygen and it doesn't even require any electricity. In a nutshell, this system works as a sort of hybrid NFT & wick system, the nutrient solution flows very slowly from one end of a flood tray and drains on the other, while on top of the flowing solution sits a second thin plastic tray with a bunch of holes in the bottom that are protruding slightly upwards to discourage water from flowing back down, this second tray is just touching the solution, not submerged in it, on top of this tray comes the membrane which is a tightly woven thin nylon fabric, this fabric is there to keep roots from growing down into the solution while still allow them to wick water up from the bottom, thus creating a constant upward movement of solution, never down, essentially keeping the solution flowing beneath in pristine condition. since the roots are always in contact with the wet fabric, due to capillary action they are coated with a thin meniscus film of nutrient solution and in that thin film is where the dissolved oxygen is highest. So i decided to go ahead and test it out, i built one according to the instructions in Andrews book and since i only have room to test this outdoors i decided to grow micro dwarf tomatoes, they stay very small and compact while still producing flowers and tomatoes and therefore have a higher nutrient demand then say lettuce.. This is what the system looks like: on the left is a 30L barrel that contains the solution, its connected with some black tubing and a valve to the bottom left side of the tray, the solution flows on the bottom of the tray and drains out the other end into a 20L collection bucket at a very slow rate, around 1 drop every 3-4 seconds, the bucket is manually dumped back into the barrel every week or so when it fills up. this is what the root zone looks like, what you see here is first the nylon fabric which sits on top of the plastic diy tray, you can see where the holes in the tray are thanks to the fabric that is being pushed up a bit. Since i started this a few weeks ago you get to see the progress without waiting This is 9 days ago: This is 5 days ago: since starting this grow the EC of my solution has not moved, PH been holding steady at 6.7, im using tap water and masterblend 4-18-38 + calcium nitrate + epsom salt as fertilizer. So far so good, i'll take more pictures tomorrow.