[semaj]

I have a 20 gal. long (2.75 watts/gal, DIY CO2, KH = 6.5) tank that was set up a few months ago - my first high light planted tank. I dose regularly with the SeaChem products and try to keep NO3 at 5-10 ppm, PO4 at 1 ppm. Right now I am growing Ludwigia, Rotala, java moss and java fern. I may not keep all of these plant species long-term, but I feel like they are forgiving while a "learn the ropes" with a high light tank.

I have noticed that many of my stem plants have developed "bare" roots above the substrate, and that the bottoms of the stems are rotting away. Since these roots are somewhat unsigtly, I was wondering what the problem is and what I can do to inhibit this above substrate root growth. I should mention that I been using Fluorite substrate by itself, but about one week ago I added some 1-3 mm course sand since I thought the large and "rough" Fluorite might be causing this problem. Any advice?

 

[travis]

IME many stem plants will develop above substrate 'air roots' until they get a firmly established under-substrate root system. The fact that you see rotting stems is a good indicator that your plants are not developing sub-surface root systems and you may want to pull a few of them to determine how badly they are disintegrating. If so, trim the rotting lower stems and replant them. If this continues you'll want to determine what may be causing the problem.

 

[trenac]

Those roots you are seeing is normal in stem plants, some more so than others. These roots can be unsightly, they can be trimmed off or another plant can be planted in front to hide these roots.

The stems rotting on the bottom is not normal and is usually caused by not enough light reaching the bottoms. Make sure that you have each stem planted further enough apart so light is able to reach that far down.

How deep is your substrate?

 

[semaj]

Thank you for the helpful advice Travis and Trenac. Just a little update:

When I added the smaller "sand" type substrate to the Fluortite, I noticed that there was almost no under-substrate root system development. This is consistent with your explanation, Travis. I just did a spot check on some of the under substrate roots, and they are now showing improved development - maybe because of the additional (and smaller) substrate I added? I will trim and replant rotting stems.

I wasn't sure if some root growth like that which I described was normal - thanks for informing me that it is. I was already planning on planting a smaller plant in front to hide these roots. I was afraid to trim them .. . since they're roots, but I will try to trim a few of the more unsightly ones. I also have probably planted the stems too close together, but when I trim and replant stems, I will be sure to place them further apart. My substrate only averages about 1.5 inches, although it is 2 inches in the back. Probably not quite deep enough, but with a 20 Gal long tank, vertical space is limited.

If I notice any other major developments in the near future, I will post an update. In the meantime, any other advice/suggestions are welcome. I really appreciate it!