Hi,
I've got a 42 UK gallon tank, sand substrate, DIY CO2 and a number of
plants. ph is 7.6, GH and KH hover around 12 degrees. I'm new to this, and
have had the tank for about 12 weeks. Initially I had a lot of plants (dont
know all their names yet), and they all seem to be growing well. However I
have had increasing trouble with the fine leaved plants such as elodea,
cabomba etc. All of them seen to rot at the base and then just float up and
swirl around in the circulation. The leaves etc seem fine, its just the base
that rots.

Any suggestions on how I can stop this ?

TIA,
Prakash.