First, try adding a one way air valve to each of the tubes on your system. They come with the petco pumps. Otherwise, they are about $2 at an aquarium store.

Second, make sure your tube is submerged under as much water as possible. If it is curling back up on itself and is therefore only a few inches below the waterline, attach something rigid to it.

If that isn’t the whole problem, try this. Take the whole Airlift tube system out of your bottle. Detatch the needleside portion of the air tubing from the little one-way valves. Blow through those air tubes to clear all the water out. Maybe leave it out to dry and if you see any waterdrops in the line. You want to try to dry out the air tubing part of it and have air pumping through it before you stick it back in the pre-filled bottom water bottle.

Here’s the logic. Water is going to want to get in to the air tubing through the needle. If it does, that water is a lot of extra “weight” that the pump has to counteract to get it’s air out of the tube before it even makes it to the needle. So dry that tubing out and then only reinsert those “guts” after you have hooked it up to the pump and the pump is on. This way it is always blowing air out so water can’t get back in.

This was our first attempt at a system using sewer pipes as reservoirs. With this particular prototype, we got to a more workable reservoir with the sewer pipes, we found we could use the top reservoir to suspend the bottles (then realized this makes cleaning difficult), and realized that lawn irrigation drip emmitter buttons do not work well. 

We had been having two issues with my tupperware reservoir system: 

1) The brass fittings that connected the tupperware container to the tubes were very difficult to attach to the soft plastic of the tupperware container. When the plastic would bend, we developed little leaks. 

2) We had been controlling the drip rate by progressively tightening clamps onto the tubes that fed each column, but we did not really have a fine enough degree of control. 

We made the switch to these PVC pipes, which are often used in traditional home-built  hydroponics systems. While there are plenty of things we don’t like about PVC, it is a cheap and easily accessible material with plenty of ready-made plumbing fittings, so it spares the beginner some headaches. 

We installed drip emmitter buttons (black and yellow pieces on the underside of the top reservoir, as seen above ) but found that they clogged frequently, not being designed to deal with the particulate matter in liquid nutrients. We have since replaced the drip emmitters with two-way aquarium air control valves, which you can pick up at your local pet shop. They are not perfect either. You do need to watch your system and occasionally clear the valves when one of your columns stops dripping. 

Luckily, the plants bounce back pretty quickly after you start the nutrient flowing again. 

Finally, we realized that after about a month and a half, there was a lot of gunk clogging up the top reservoir and that we needed to clean it way more often– like every two weeks. It became apparent that suspending the columns from the top reservoir was not a good idea because then you have to take apart the whole system to clean the top tube. You will see that in the current how-to, we recommend hanging the columns separately.

In this system, we merely hung the CFL lights by their cords flat against the window and plants grew out toward them.