Carol, if you are going by "the WPG rule" that is where some of your problem may be, that does not work as you are seeing, on a tank that size, the algae and plants are telling you so.
The plants and algae are your ultimate test kit, in a low tech tank with the algae issue's you are talking about, you have to much light.
I have a couple low tech tanks running for a few years now, if I added more light without C02, you can bet they would burst out with algae rather fast.
If you either reduce the light intensity, or add C02 you would see a big difference either way.
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