Black spots on Plants

[Buckaroo]

Hello all,

I would need your help to identify a problem I am having...
I noticed today that I have some black spots on my plants...
also some holes.

background on the tank:

This tank has been up and running for the last year.  It is planted with unknown plants (never can remember them).  I don't fertilize (which might be my problem).  It's a 44G tank that has 7 neon, 2 balla shark, 2 gourami (1 small+1 big), 2 american flag fish, 1 betta and 2 guppie.

I clean my tank weekly with a 5G water change with tap water (with water conditionner).

attached are some pics of the plants.

thanks for your help.

Buckaroo

[BigDaddy]

What you have there is a little bit of green spot algae.

How much light is over that tank?  How tall is the tank?

[Buckaroo]

I don't have that much light yet...

I only have 30W of lights....and it's 22 inches tall.

the problem here is I don't want to have a big canopy over the tank.

can I treat this problem....?

thanks