Algae in substrate

Question
Hello, I have a 240L freshwater setup that has been up and running for at least 6 weeks now.  I use a white coral sand substrate in effort to raise my kH, but doesn't really work.  About 2 weeks ago I noticed my plants were dying so I took out my pleco(thinking she was eating them) and added 5 siamese algae eaters.  Although the plants didnt have any algae on them, algae appeared more on the glass, so I put my pleco back in and the glass problem has been solved.  It also appears that my plants are neglected of CO2 so I am working on getting a CO2 system next.

Now my issue is in the substrate.  The sand appears brownish with some little hints of green scattered throught. I siphoned it out and it pops back up in about a day.  So pretty much if I siphon it every day the gravel looks good, but I don't think I am supposed to siphon it every day.  My regular maintenance consist of 15 to 25% water changes every week through a siphon.  I add water conditioner and used to add fertilizer the next day, but stopped because i read somewhere that if my plants arent growing then the algae is eating the fertilizer.  Nitrates and nitrites are good and I don't change but one filter pad, the cotton one, every week.

Do you think that maybe I should change out the gravel to something darker so it isn't as noticeable or should I just pull out the gravel, clean it, clean the bottom of the tank, and then put the gravel back in?  I raise my KH with baking soda now so I am not to worried about the hardness anymore.  Thanks.

Answer
Hi Walkman;

That's the drawback of white gravel I'm afraid. The only permanent solution is to use a darker one so you don't see the algae and detritus so much. More live plants to shade the gravel would really help. Maybe you could get a CO2 going and try that first? If the algae can't get direct light it really can't grow very well. Or, put in some artificial plants to do it temporarily and then change them out as you add live ones.

Hope it all works out okay.......

At Your Service;
Chris Robbins