Definately get Test Kits, strips aren't good enough. Your tank should be stable now at eight months but those Nitrates, if that reading is accurate, are way to high. Personally I don't like mine over 10ppm. About the algae, test your water for Phosphates (or go to the LFS
and ask them to test it for you.) if you have high Phosphates buy someting called a Phosphate sponge. It's reusable and really good at removing all your Phosphates (it floored mine). This should decrease algae growth rates because what algae needs to grow is Phosphates, Nitrates and Light. Your Nitrates are too high (aim for below 10ppm), we don't know about your Phosphates but if the algae is growing that quick then they are probably high, and how long do you have your lights on per day?
How often is 'periodically' also? Cutting back on the food was a good idea as Phosphates come from food too. (Try rinsing the brine shrimp cube in Fresh Water also before you put it in, this removes extra 'phates).