Hi guys, need your inputs in this. My 18L (36cm) tank is illuminated by a Aquazonic T5HO 8W x 2 12000k "sun" tubes. Is this too overkill for the tank? should i cut it to only 8 W?

Plants list for the tank are:

Marselia Hirsuta
Java Fern/Windelov Mini variation
Bolbitis

Flame/Taiwan/Spkiy/Java moss

Small stalks of water wisteria and bacopa caroliniana

Any advice would be appreciated.

Note: The main reason i chose the T5 lighting because i wanted the light to be spread ed out evenly across the tank, hand a PL lightset before and it didn't perform properly.. A bit of Green spot algae on the glass only so far.. Tank have been running for just over 2 months on the T5