Whats The Cause

[modaz]

everytime i put new plants in this happens
substrate-sand
temp 75f/24c
good light 10 hours a day

 

[cheesy feet]

Sand looks like it's rotting the plants roots/stem,this happens in my planted tank with sand.You might want to switch to gravel.

 

[Neo8223]

holy cow! Assuming the problem was the sand, a quick fix if you didnt want to change the sand, may be to have pots. However, they would have to be partially submerged from the sand and this wouldnt look too good.

 

[reiverix]

It could be that the sand is suffocating the stems. Try putting a plant weight around the individual stems, just enough to hold the plant down and let it sit on the substrate. It will start shooting out roots to anchor itself in, and then you can remove the weights. Is that ammania?

 

[Dave Spencer]

It is not the sand as far as I can tell. I have hundreds of stems growing quite happily in my sand.

Is the plant in the picture Rotala Rotundifolia? If so, it looks as if it is in its emergent state (thick red stem), but will change to its submerged state of a thin green stem with thin green leaves. One or two of my stems did this as well when I initially carried out a major planting session. Just take off the black, rotting part and carefully replant the stem, being careful not to snap it.

Dave.

 

[nightlite]

one of the harder plants......you need ferts with lots of Iron and plenty of lights...and root tabs at its roots too if you only have sand as substrate

and also don't plant them too close to each other

 

[Graeme Edwards]

Looks like your plants are are rottong from the bottom up.
This is proberbly because they are in sand. Sand can get "anerobic" ( toxic enviroment with no oxygen) and will kill most plants. The sand will starve the root of oxygen.
Plus the plant looks like a very demanding plant, requiering, High light, High Co2 and plenty of fertilizers. So you may always struggle with that plant, unless you go high tech!

Regards,
Graeme.