Whiteish, does not sound like algae at all - it sounds more like a bacterial bloom which is not uncommon in newly established tanks. This usually clears itself up without intervention.
The best algae eating fish is the Siamese Algae Eater, Crossocheilus siamensis, but this is a species that needs to be kept in groups and grows too large for your tank. For small tanks, Ottocinclus species are best, although they will not eat all types of algae.