will this idea work?

looks fine but why do you have scrubbies AND sponges? isn't one or the other fine?
also i think that the W Lettuce would need to SIT in water rather than just be dowsed with running water, so make sure there's enough water in there to support it.

oh well then it seem fine.

No it isn't going to work.

1. The water lettuce needs the water to enter below the surface.
2. The media needs positive flow through it; just sitting in the water will not get the job done.
3. The buckets will act as a restriction. Water will take the path of least resistance, which will mean going around the buckets.
4. The filter fiber will not work unless the water is flowing directly through it and has no where to escape except by going through it. Otherwise, as soon as it starts to get dirty the water will start going out the first holes it comes to.

What you should do:
1. Stack the buckets and have the top buckets drilled only on the bottom. This will guarantee flow through the mechanical filter (fiber).
2. The lower buckets can be drilled on the sides. Put scrubbies in them.
3. Elevate the buckets so that the rims of the top buckets are slightly above the water line. This will force the water in a downward direction through the media.
4. Have your return pipe teed to divide the water between the top buckets.
5. Place the water lettuce between the top buckets.

Here's something I didn't think about and you didn't mention...Do the buckets fit tightly in the filter tank? It will work if they do. But you should make a square container for the filter floss. You could also use lids on the buckets and then plumb the return water to holes in the lids. The plumbing inside the filter does not need to be glued so it can be taken apart for cleaning. By putting the lids on the buckets, you can submerge them and have the water lettuce over the entire surface.

also what if the plexiglass was in front of the plants? allowing the water to flow down and not land on top of them?

CHOMPERS;775880; said:

3. The buckets will act as a restriction. Water will take the path of least resistance, which will mean going around the buckets.

Click to expand...

I think this would be the biggest problem. Why don't you silicon in some baffles and just set it up like an ordinary sump?

Then you could still make trickle towers with the buckets if you wanted to.