Need help as a newbie: leaves rotting/plants dying

[ruincccc]

Hello, I recently set up a 40 G breeder to try out a planted tank. The tank is fully cycled just the plants are new. I planted the plants over 3 inches of lava rock/soil mix, and let the plants settle for 1 week before adding fish (a few 2'' Amazon puffer) back. I have the light scheduled with 8 hours on time. it has been about 3 weeks, but the leaves are rotting and plants even drying, can someone help with anything I may have done wrong? too much light? too little light?

 

[FINWIN]

Hi. I'm no no expert on plants, but Seachem flourish should help. I've been going back to real plants somewhat. I had trouble with hornwort! I discovered some plants don't like being rooted and do better floating. I find the seachem really helps plants acclimate after shipping...I put mine in a white bucket under bright led light while they soak in seachem for a week or so. I use higher doses to get them started...right now I have a mushy red sword I'm nursing back to health and its finally responding.

The hornwort was weird...90% mush in every tank except one, but it's taking off now. Oxygenation helps a lot. Root tabs in the substrate is an option too.