The original wood was from the beach, and i soaked and suned it before use.
I like the new wood better now anyway.
I stripped the tank as:
*it wasnt snails
*I dont think it was the water hardness as my other tank has some of the same platns and they have been thriving.
*Dont think it was lighting as they are new lights and I have less per litre on my other tank and things are fine.
*I think the flourish may have hurt the val but the other plants were bad before i started using the flourish
*I do a weekly water change and tests showed water quality wasnt a problem.
*The tank has been running for over 3 months so it wasnt new tank problems
*I have aquatic mix and prrpagaing sand in both my tanks, so i dont think substrate was a problem.
*I have clown loaches but the plants were coming up as the had obviosly rotted through.
*I have ambulia, not cabomba.
So the only thing i could think to do was to pull it all apart and start over.
The only thing i could think of that could have been causing problems was the wood, as it may have been leeching something into the water.
Im happy with what ive done and im keen to see if it solves the problem.