Algae In Fish Tank

Question
Hi Karen,

I have some problems with my planted tank and would appreciate your expert advise.

I have a 3ft planted tank and keep mostly Tetras.  Lately, I noticed a layer of think brown slimely substance sticking to most part of the 4 panels of the tank.   This include the leaves of the plants.  Although they can be easily removed by wiping them off with a sponge, it is rather time consuming especially getting rid of them  from the plants.  Besides, they will appear again after a couple of days.  Conversely, in the past when I didn't have this problem, I noticed that certain fishes especially the Rummy Nose Tetras didn't display this full red color on their nose.  Now, with this thin slimely, the Rummy Nose Tetras look better with a full red spot on their nose.

I am starting to wonder if this slimely substance has anything to do with my lighting.  I use a two and a half foot 30W white flourscent tube (to simulate daylight) and at the same time, I am told, is good for the plants' growth.  I previously used a combination of 2 x 25W white and warm flourescent tubes and the slimely substance was not there.

What is this thin slimely substance and the cause of it?  Is there any way I can get rid of it permanently?

Answer
Dear Lawrenz,
Sounds like you have Brown algae. Also known as Diatoms that flourish in low-light and/or high nutrient aquariums. Sometimes this is common in somewhat new aquariums as well.
Fortunately it often goes away once things get established and settled but may persist should the nitrate levels be consistantly high. Definately try vacumming the gravel (in areas where you do not disturb plants) and increase your water change schedule. Insure your filters are clean and not clogged also. It could in fact be due to low light levels in your aquarium and one indicator is you once had a combined total of 50watts of lighting. But usually brown algae isn't a reoccuring problem especially with planted tanks as long as the water quality is insured to be good and healthy.

Some algae eaters can help with brown algae problems such as my favorite the Bristlenose pleco. Ottocinclus catfish and Siamese algae eaters are also well know for eating brown algae. But I might try the Bristlenose as these are among the best most reliable algae eaters with the added plus that they do not grow large, and don't wreck havoc on your aquarium plants.

I really hope this helps!
Happy water gardening!
Best wishes,
Karen~