Plants Sick?

hello all
I have some plants that have been getting black only in the bottom of the leaves does any body now? I have some pictures I can post them later

ok thanks for the help

Pictures will help alot. Also do you know what kinds of plants they are?

Tank stats will also help.

Tank size?
Lighting? What type and how much? How long are they on for?
Any CO2?
Any nutrients being added?
Water change regime?
How much flow? (your filters should have a rated litre per hour)

As mentioned already, pictures could help. There's a chance the plants could be non-aquatic.

hi thanks for the replys my tank is a 31 gallon
24w t5
and a home made co2
I can't remember the name of the plant lol

anybody??
or is this normal for the plant ??