You said you don't use CO2, but do you use liquid carbon? Liquid carbon used at the recommended dosage (if it starts to melt any plants, cut to a 1/2 dose) should help. Proper fertilization helps because the plants use the nutrients before the algae can. Plants can out compete algae if conditions are good. Also is this a new tank? You don't mention what kind of algae you have. If it is brown algae, which are really diatoms, it generally goes away as the tank ages. Some algae is well controlled by algae eating animals. Many use Amano shrimp or even the lowly snail, including so called nuisance snails. As long as the snails don't eat the plants, and mine don't, I personally consider them a help rather than a problem.