algae?

Question
hi
i was cleaning my tank today and noticed that on the substrate there was a large amount of green algae growing which i thought was odd considering the substrate is fine sand. also there is a large amount of brown algae growing on the back wall of my tank (which for some odd reason is being left alone by my tiger and porcupine nerite snails). the main problem is the algae on the sand as i cant remove it without taking a large quantity of sand with it and it is very unsightly. also as i have 5 peppered catfish shouldnt they be eating algae on the substrate?

any suggestions as to how i can rid my tank of this algae would be much appreciated.
thanks..

Answer
Hi,
the main reason tanks develop an overabundance of algae is usually a sign that the tank is out of balance in either light or nutrients. When there is too much light and nutrients the algae will thrive and possibly overrun the tank.

Unfortunately, corydoras catfish aren't much fans of eating algae like plecostomus or otocinclus. But I don't think even those fish would be able to clean the algae off the sand like they would with a large grain gravel.

I think the best thing to do is start more frequent partial water changes until the situation gets better. Try to do a partial water change of about 30% two or three times a week and make sure to keep the sand bed disturbed to avoid "dead spots" where it gets too tightly packed and bad bacteria can thrive.

And cut back on the light as much as possible to deter the algae. Later on make sure to only keep your tank lights on for about 10-12 hours. Perhaps turn them off during the day some for a short period when you aren't home just as long as the fish wont be plunged into complete darkness.

Eventually whichever need the algae is thriving on will be depleted and the algae should go away. If even after a couple of weeks this doesn't work. You might want to have your water tested for nitrates or other pollutants that may be fueling the algae growth.

I do hope this helps!
Karen~