[cs_gardener]

Instead of making a curtain of the vals in back, how about moving them all to one corner (I'm thinking left behind the wood) and then adding some stem plants like Rotala sp. green, or a colorful crypt. Also, look through the PlantFinder to see what plants would do well in your tank and what you like. Have you looked at the Marsilea species for a foreground? (see here) They will grow well with lower light and they do stay reasonably short.

 

[cs_gardener]

I see the pattern on the back, I guess I just figured it was a background you'd used on purpose. I don't know how you'd get off that type of stain. I've had some luck with scraping some deposits off using a razor blade but it works best with an empty tank. Hmmmm, how about a moss wall?

 

[cs_gardener]

Some of the ferns would provide some good coverage in the back. They grow slowly but Bolbitis huedeloti and narrow leaf or lace leaf java fern would eventually make a nice mass. I tie them onto some driftwood I found that isn't too visually appealing so I can move them around as I like, rocks work well too but it's harder to get the ferns "up" if that's the look I'm after. Also, there are some nice crypts that would be suitable. My Crypt spiralis took over a corner of the tank and has formed a dense mass and crypt wendtii red or bronze would be a nice contrast to the various greens. A stem plant or two would be a nice contrast to ferns and crypts. I think you'd be pleased with 3-5 different background plants to create some interest, especially if you keep them at different heights.

 

[cs_gardener]

Looks like a good plan. The P gayi is a more open, airy plant so it should do fine in front of the Ludwigia. If it gets too tall it's very easy to trim. When it's happy it will send out runners everywhere, so you might want to consider a containment system for it.

I noticed that your background plantings are all about the same size. I did that in a tank and changed it later so some were bigger and others smaller - it looked a bit too regulated when the groups were all the same size. I realize this is just a general sketch, but it's something to consider when you're planting.

 

[cs_gardener]

does it grow as fast as corkscrew val?

It's growth rate depends on how happy it is with its conditions. I had it in one tank and it spread through all the stems plants in a couple weeks without me noticing it. Such a pain trying to get it out. It's now growing quite slowly in a different tank (thankfully!) and I have it boxed in by rocks so any runners will have to jump over the rocks and will be easy to see and pull.

Instead of using a cup you could cut a ring out of the center of a 2 liter pop bottle. It would be pretty easy to shape it into whatever you like and clear plastic shouldn't be too noticeable in a tank. Once it's pushed into the substrate it should be sturdy enough to keep the runners contained (or jumping the corral so it's easy to see them).