Rotting Stem Plants?

[Tessla]

I've been planted for a few months now (with a great deal of help from posters on this forum!) but I haven't been able to solve this particular problem. Frequently, when adding new stem plants, parts of the stem and sometimes the entire stem will turn brown-black and melt away. The pieces that don't melt and continue to grow are always perfectly fine, I haven't seen this happen to any new growth. I've also had several anubias (also new plants, anything that's already rooted in is fine) where the rhizome rotted away and the leaves fell off while still a very healthy green. Some of them have been mail order, some have come from various LFS so it must be something to do with handling or water conditions? Just wondering what sorts of things could be causing this as something must be shocking my new plants.

This has happened to: hygrophila, bacopa caroliniana, rotala, foxtail and anubias, the only two I lost completely were the bacopa caroliniana and foxtail, the rest have lots of new growth and I've managed to get a few anubias growing again from just the roots.

I've had no problems with: swords, cryptocorynes, java fern, java moss, anacharis or marimo balls.

Two different tanks, one with sand only substrate and 2 wpg, the other with soil under sand and 1.5 wpg. Water has a pH of 8 from the tap, is very hard and has near the legal limit of nitrate among other things. Both tanks stay a bit above 8 but no higher than 8.4. Virtually no algae in either recently, a bit of brown algae in the first tank which was fixed by decreasing the lighting hours.

 

[Dave Spencer]

I have had the odd stem rot at the base, and these are planted in sand. Apparently, sand can become compacted and restrict the roots from growing and deprive them of O2. You may need to occassinally gently poke around the sand to loosen it up a little.

Are you adding ferts of any kind to the 2WPG sand only tank?

Dave.

 

[fishboy619]

have any of them got weight around them, maybe they are too tight.

 

[Tessla]

Root tabs under the swords and crypts, occasionally a bit of the liquid Seachem ferts but that's about it. I also remove all of the weights, plastic pots and wool around the roots before planting and seperate out my stem plants a bit so that they aren't all bunched together. Java fern and anubias are attached to wood, so the rhizomes aren't anywhere near the substrate.

The rot also usually starts in the middle of the stem, which makes me wonder if I'm just getting damaged stems in the first place or not being careful enough while handling.

 

[fishstick]

I have similar problem with vallis, it just melts within three or four days of putting it in. My water v. hard , other stats ok.