Goldfish love algae and plants. I let the algae grow on my back wall just to feed the goldfish. As for the peas, they are a good treat but shouldn't be part of a goldfish's staple diet as they are a suggary veggie and goldfish need more leafy, fibery veggies than suggary ones. Peas are not as good for digestion as most people think; the people that feed peas and then see an improvement are those who feed flake or low-quality pellet food. Any type of green in an improvement from that. Spinach is actually much better for goldfish digestions as it actually has a laxative and anti-inflammatory properties.